System and methods for rapid round-trip-time measurement distribution

ABSTRACT

Disclosed are techniques for determining round-trip time (RTT) of a user equipment (UE). In an aspect, each gNodeB in a plurality of gNodeBs measure signaling data related to an uplink RTT reference signal received from the UE and the downlink RTT reference signal transmitted by each gNodeB. The signaling data comprises one of a processing delay between a time of arrival (TOA) of the uplink RTT reference signal and a time of transmission (TOT) of the downlink RTT reference signal or a total RTT between the TOT of the downlink RTT reference signal and the TOA of the uplink RTT reference signal. The signaling data is sent to a single entity, other than the UE, e.g., another gNodeB or a location server, where signaling data relevant to the UE is aggregated. The aggregated signaling data may be sent to the UE to determine the RTT for the UE or used by the location server to determine the RTT for the UE.

CLAIM OF PRIORITY UNDER 35 U.S.C. § 119

This application claims under 35 USC § 119 the benefit of and priorityto U.S. Provisional Application No. 62/742,205, filed Oct. 5, 2018, andentitled “SYSTEM AND METHODS FOR RAPID ROUND-TRIP-TIME MEASUREMENTDISTRIBUTION,” which is assigned to the assignee hereof and isincorporated herein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

Aspects of the disclosure relate to round trip time (RTT) estimationprocedures.

Relevant Background

Wireless communication systems have developed through variousgenerations, including a first-generation analog wireless phone service(1G), a second-generation (2G) digital wireless phone service (includinginterim 2.5G and 2.75G networks), a third-generation (3G) high speeddata, Internet-capable wireless service and a fourth-generation (4G)service (e.g., LTE or WiMax). There are presently many different typesof wireless communication systems in use, including Cellular andPersonal Communications Service (PCS) systems. Examples of knowncellular systems include the cellular Analog Advanced Mobile PhoneSystem (AMPS), and digital cellular systems based on Code DivisionMultiple Access (CDMA), Frequency Division Multiple Access (FDMA), TimeDivision Multiple Access (TDMA), the Global System for Mobile access(GSM) variation of TDMA, etc.

A fifth generation (5G) mobile standard calls for higher data transferspeeds, greater numbers of connections, and better coverage, among otherimprovements. The 5G standard, according to the Next Generation MobileNetworks Alliance, is designed to provide data rates of several tens ofmegabits per second to each of tens of thousands of users, with 1gigabit per second to tens of workers on an office floor. Severalhundreds of thousands of simultaneous connections should be supported inorder to support large sensor deployments. Consequently, the spectralefficiency of 5G mobile communications should be significantly enhancedcompared to the current 4G standard. Furthermore, signaling efficienciesshould be enhanced and latency should be substantially reduced comparedto current standards.

SUMMARY

The following presents a simplified summary relating to one or moreaspects disclosed herein. As such, the following summary should not beconsidered an extensive overview relating to all contemplated aspects,nor should the following summary be regarded to identify key or criticalelements relating to all contemplated aspects or to delineate the scopeassociated with any particular aspect. Accordingly, the followingsummary has the sole purpose to present certain concepts relating to oneor more aspects relating to the mechanisms disclosed herein in asimplified form to precede the detailed description presented below.

In one aspect, a method for determining a round-trip time (RTT) forsignals between a user equipment (UE) and a plurality of network nodes(gNodeBs) in a wireless network performed by the UE, includestransmitting, to at least a first gNodeB and a second gNodeB, an uplinkRTT reference signal; receiving, from each of the first gNodeB and thesecond gNodeB, downlink RTT reference signals, wherein each of the firstgNodeB and the second gNodeB measure signaling data related to theuplink RTT reference signal and the downlink RTT reference signaltransmitted by the first gNodeB and the second gNodeB, wherein thesignaling data comprises one of a processing delay between a time ofarrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal; receiving, from a single entity in thewireless network, an aggregated report of the measured signaling datafor the first gNodeB and the second gNodeB; and calculating a net RTTbetween the UE and each of the first gNodeB and the second gNodeB basedon the measured signaling data for the first gNodeB and the secondgNodeB received in the aggregated report and corresponding signalingdata measured by the UE, wherein the corresponding signaling datacomprises one of a total RTT between the TOT of the uplink RTT referencesignal and the TOA of the downlink RTT reference signal or a processingdelay between the TOA of the downlink RTT reference signal and a TOT ofthe downlink RTT reference signal, and the net RTT is determined usingthe total RTT and the processing delay.

In one aspect, a user equipment (UE) configured for determining around-trip time (RTT) for signals between the UE and a plurality ofnetwork nodes (gNodeBs) in a wireless network, includes a transceiver ofthe UE configured to: transmit, to at least a first gNodeB and a secondgNodeB, an uplink RTT reference signal; receive, from each of the firstgNodeB and the second gNodeB, downlink RTT reference signals, whereineach of the first gNodeB and the second gNodeB measure signaling datarelated to the uplink RTT reference signal and the downlink RTTreference signal transmitted by the first gNodeB and the second gNodeB,wherein the signaling data comprises one of a processing delay between atime of arrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal; receive, from a single entity in thewireless network, an aggregated report of the measured signaling datafor the first gNodeB and the second gNodeB; at least one memory; and atleast one processor of the UE coupled to the transceiver and the atleast one memory and configured to calculate a net RTT between the UEand each of the first gNodeB and the second gNodeB based on the measuredsignaling data for the first gNodeB and the second gNodeB received inthe aggregated report and corresponding signaling data measured by theUE, wherein the corresponding signaling data comprises one of a totalRTT between the TOT of the uplink RTT reference signal and the TOA ofthe downlink RTT reference signal or a processing delay between the TOAof the downlink RTT reference signal and a TOT of the downlink RTTreference signal, and the net RTT is determined using the total RTT andthe processing delay.

In one aspect, a user equipment (UE) configured for determining around-trip time (RTT) for signals between the UE and a plurality ofnetwork nodes (gNodeBs) in a wireless network, includes means fortransmitting, to at least a first gNodeB and a second gNodeB, an uplinkRTT reference signal; means for receiving, from each of the first gNodeBand the second gNodeB, downlink RTT reference signals, wherein each ofthe first gNodeB and the second gNodeB measure signaling data related tothe uplink RTT reference signal and the downlink RTT reference signaltransmitted by the first gNodeB and the second gNodeB, wherein thesignaling data comprises one of a processing delay between a time ofarrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal; means for receiving, from a single entityin the wireless network, an aggregated report of the measured signalingdata for the first gNodeB and the second gNodeB; and means forcalculating a net RTT between the UE and each of the first gNodeB andthe second gNodeB based on the measured signaling data for the firstgNodeB and the second gNodeB received in the aggregated report andcorresponding signaling data measured by the UE, wherein thecorresponding signaling data comprises one of a total RTT between theTOT of the uplink RTT reference signal and the TOA of the downlink RTTreference signal or a processing delay between the TOA of the downlinkRTT reference signal and a TOT of the downlink RTT reference signal, andthe net RTT is determined using the total RTT and the processing delay.

In one aspect, a non-transitory storage medium including program codestored thereon, the program code is operable to cause at least oneprocessor in a user equipment (UE) to determine a round-trip time (RTT)for signals between the UE and a plurality of network nodes (gNodeBs) ina wireless network, includes program code to transmit, to at least afirst gNodeB and a second gNodeB, an uplink RTT reference signal;program code to receive, from each of the first gNodeB and the secondgNodeB, downlink RTT reference signals, wherein each of the first gNodeBand the second gNodeB measure signaling data related to the uplink RTTreference signal and the downlink RTT reference signal transmitted bythe first gNodeB and the second gNodeB, wherein the signaling datacomprises one of a processing delay between a time of arrival (TOA) ofthe uplink RTT reference signal and a time of transmission (TOT) of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; program code to receive, from a single entity in the wirelessnetwork, an aggregated report of the measured signaling data for thefirst gNodeB and the second gNodeB; and program code to calculate a netRTT between the UE and each of the first gNodeB and the second gNodeBbased on the measured signaling data for the first gNodeB and the secondgNodeB received in the aggregated report and corresponding signalingdata measured by the UE, wherein the corresponding signaling datacomprises one of a total RTT between the TOT of the uplink RTT referencesignal and the TOA of the downlink RTT reference signal or a processingdelay between the TOA of the downlink RTT reference signal and a TOT ofthe downlink RTT reference signal, and the net RTT is determined usingthe total RTT and the processing delay.

In one aspect, a method for determining a round-trip time (RTT) forsignals between a user equipment (UE) and a plurality of network nodes(gNodeBs) in a wireless network performed by a first gNodeB in theplurality of gNodeBs, includes receiving, from the UE, an uplink RTTreference signal; transmitting, to the UE, a downlink RTT referencesignal; measuring signaling data related to the uplink RTT referencesignal and the downlink RTT reference signal, wherein the signaling datacomprises one of a processing delay between a time of arrival (TOA) ofthe uplink RTT reference signal and a time of transmission (TOT) of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; and sending, to an entity in the wireless network other than theUE, a report of the signaling data.

In one aspect, a network node (first gNodeB) in a wireless networkconfigured for determining a round-trip time (RTT) for signals between auser equipment (UE) and a plurality of network nodes (gNodeBs), includesat least one transceiver configured to: receive, from the UE, an uplinkRTT reference signal; transmit, to the UE, a downlink RTT referencesignal; at least one memory; and at least one processor coupled to theat least one transceiver and the at least one memory and configured tomeasuring signaling data related to the uplink RTT reference signal andthe downlink RTT reference signal, wherein the signaling data comprisesone of a processing delay between a time of arrival (TOA) of the uplinkRTT reference signal and a time of transmission (TOT) of the downlinkRTT reference signal or a total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal; and theat least one transceiver is further configured to: sending, to an entityin the wireless network other than the UE, a report of the signalingdata.

In one aspect, a network node in a wireless network configured fordetermining a round-trip time (RTT) for signals between a user equipment(UE) and a plurality of network nodes (gNodeBs), includes means forreceiving, from the UE, an uplink RTT reference signal; means fortransmitting, to the UE, a downlink RTT reference signal; means formeasuring signaling data related to the uplink RTT reference signal andthe downlink RTT reference signal, wherein the signaling data comprisesone of a processing delay between a time of arrival (TOA) of the uplinkRTT reference signal and a time of transmission (TOT) of the downlinkRTT reference signal or a total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal; andmeans for sending, to an entity in the wireless network other than theUE, a report of the signaling data.

In one aspect, a non-transitory storage medium including program codestored thereon, the program code is operable to cause at least oneprocessor in a first network node (gNodeB) in a wireless network tooperate for determining a round-trip time (RTT) for signals between auser equipment (UE) and a plurality of network nodes (gNodeBs) in thewireless network, includes program code to receive, from the UE, anuplink RTT reference signal; program code to transmit, to the UE, adownlink RTT reference signal; program code to measure signaling datarelated to the uplink RTT reference signal and the downlink RTTreference signal, wherein the signaling data comprises one of aprocessing delay between a time of arrival (TOA) of the uplink RTTreference signal and a time of transmission (TOT) of the downlink RTTreference signal or a total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal; andprogram code to send, to an entity in the wireless network other thanthe UE, a report of the signaling data.

In one aspect, a method for determining a round-trip time (RTT) forsignals between a user equipment (UE) and a plurality of network nodes(gNodeBs) in a wireless network performed by a first gNodeB in theplurality of gNodeBs, includes receiving, from the UE, an uplink RTTreference signal; transmitting, to the UE, a downlink RTT referencesignal; measuring, by the first gNodeB, first signaling data related tothe uplink RTT reference signal and the downlink RTT reference signal,wherein the first signaling data comprises one of a processing delaybetween a time of arrival (TOA) of the uplink RTT reference signal and atime of transmission (TOT) of the downlink RTT reference signal or atotal RTT between the TOT of the downlink RTT reference signal and theTOA of the uplink RTT reference signal; receiving, from a second gNodeB,a report of a second signaling data measured by the second gNodeBrelated to the uplink RTT reference signal received by the second gNodeBand a second downlink RTT reference signal transmitted by the secondgNodeB, wherein the second signaling data comprises one of a secondprocessing delay between a TOA of the uplink RTT reference signal at thesecond gNodeB and a TOT of the second downlink RTT reference signal or asecond total RTT between the TOT of the second downlink RTT referencesignal and the TOA of the second uplink RTT reference signal;aggregating the signaling data and the second signaling data; andtransmitting, to the UE, an aggregated report of the signaling data andthe second signaling data.

In one aspect, a network node (first gNodeB) in a wireless networkconfigured for determining a round-trip time (RTT) for signals between auser equipment (UE) and a plurality of network nodes (gNodeBs), includesat least one transceiver configured to: receive, from the UE, an uplinkRTT reference signal; transmit, to the UE, a downlink RTT referencesignal; receive, from a second gNodeB, a report of a second signalingdata measured by the second gNodeB related to the uplink RTT referencesignal received by the second gNodeB and a second downlink RTT referencesignal transmitted by the second gNodeB, wherein the second signalingdata comprises one of a second processing delay between a TOA of theuplink RTT reference signal at the second gNodeB and a TOT of the seconddownlink RTT reference signal or a second total RTT between the TOT ofthe second downlink RTT reference signal and the TOA of the seconduplink RTT reference signal; at least one memory; and at least oneprocessor coupled to the at least one transceiver and the at least onememory and configured to: measure, by the first gNodeB, first signalingdata related to the uplink RTT reference signal and the downlink RTTreference signal, wherein the first signaling data comprises one of aprocessing delay between a time of arrival (TOA) of the uplink RTTreference signal and a time of transmission (TOT) of the downlink RTTreference signal or a total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal;aggregate the signaling data and the second signaling data; and whereinthe at least one transceiver is further configured to transmit, to theUE, an aggregated report of the signaling data and the second signalingdata.

In one aspect, a network node (first gNodeB) in a wireless networkconfigured for determining a round-trip time (RTT) for signals between auser equipment (UE) and a plurality of network nodes (gNodeBs), includesmeans for receiving, from the UE, an uplink RTT reference signal; meansfor transmitting, to the UE, a downlink RTT reference signal; means formeasuring, by the first gNodeB, first signaling data related to theuplink RTT reference signal and the downlink RTT reference signal,wherein the first signaling data comprises one of a processing delaybetween a time of arrival (TOA) of the uplink RTT reference signal and atime of transmission (TOT) of the downlink RTT reference signal or atotal RTT between the TOT of the downlink RTT reference signal and theTOA of the uplink RTT reference signal; means for receiving, from asecond gNodeB, a report of a second signaling data measured by thesecond gNodeB related to the uplink RTT reference signal received by thesecond gNodeB and a second downlink RTT reference signal transmitted bythe second gNodeB, wherein the second signaling data comprises one of asecond processing delay between a TOA of the uplink RTT reference signalat the second gNodeB and a TOT of the second downlink RTT referencesignal or a second total RTT between the TOT of the second downlink RTTreference signal and the TOA of the second uplink RTT reference signal;means for aggregating the signaling data and the second signaling data;and means for transmitting, to the UE, an aggregated report of thesignaling data and the second signaling data.

In one aspect, a non-transitory storage medium including program codestored thereon, the program code is operable to cause at least oneprocessor in a first network node (gNodeB) in a wireless network tooperate for determining a round-trip time (RTT) for signals between auser equipment (UE) and a plurality of network nodes (gNodeBs) in thewireless network, includes program code to receive, from the UE, anuplink RTT reference signal; program code to transmit, to the UE, adownlink RTT reference signal; program code to measure, by the firstgNodeB, first signaling data related to the uplink RTT reference signaland the downlink RTT reference signal, wherein the first signaling datacomprises one of a processing delay between a time of arrival (TOA) ofthe uplink RTT reference signal and a time of transmission (TOT) of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; program code to receive, from a second gNodeB, a report of asecond signaling data measured by the second gNodeB related to theuplink RTT reference signal received by the second gNodeB and a seconddownlink RTT reference signal transmitted by the second gNodeB, whereinthe second signaling data comprises one of a second processing delaybetween a TOA of the uplink RTT reference signal at the second gNodeBand a TOT of the second downlink RTT reference signal or a second totalRTT between the TOT of the second downlink RTT reference signal and theTOA of the second uplink RTT reference signal; program code to aggregatethe signaling data and the second signaling data; and program code totransmit, to the UE, an aggregated report of the signaling data and thesecond signaling data.

In one aspect, a method for determining a location for a first userequipment (UE) using round-trip time (RTT) for signals between the firstUE and a plurality of network nodes (gNodeBs) in a wireless networkperformed by a location server, includes receiving, from a first gNodeB,a report of first signaling data related to a time of arrival (TOA) ofuplink RTT reference signals received by the first gNodeB from aplurality of UEs including the first UE and time of transmission (TOT)of downlink RTT reference signals transmitted by the first gNodeB toeach of the plurality of UEs, wherein for each UE in the plurality ofUEs, the first signaling data comprises one of a processing delaybetween the TOA of the uplink RTT reference signal and the TOT of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; receiving, from a second gNodeB, a report of second signalingdata related to the TOA of uplink RTT reference signals received by thesecond gNodeB from the plurality of UEs including the first UE and TOTof downlink RTT reference signals transmitted by the second gNodeB toeach of the plurality of UEs, wherein for each UE in the plurality ofUEs, the second signaling data comprises one of the processing delaybetween the TOA of the uplink RTT reference signal and the TOT of thedownlink RTT reference signal or the total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; and aggregating, for the first UE in the plurality of UEs, thefirst signaling data and the second signaling data; and wherein thelocation of the UE is determined using at least a net RTT between thefirst UE and each of the first gNodeB and the second gNodeB, wherein thenet RTT is determined using the first signaling data and the secondsignaling data aggregated for the first UE.

In one aspect, a network node (location server) in a wireless networkconfigured for determining a location for a first user equipment (UE)using round-trip time (RTT) for signals between the first UE and aplurality of network nodes (gNodeBs), includes at least one networkinterface configured to: receive, from a first gNodeB, a report of firstsignaling data related to a time of arrival (TOA) of uplink RTTreference signals received by the first gNodeB from a plurality of UEsincluding the first UE and time of transmission (TOT) of downlink RTTreference signals transmitted by the first gNodeB to each of theplurality of UEs, wherein for each UE in the plurality of UEs, the firstsignaling data comprises one of a processing delay between the TOA ofthe uplink RTT reference signal and the TOT of the downlink RTTreference signal or a total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal;receive, from a second gNodeB, a report of second signaling data relatedto the TOA of uplink RTT reference signals received by the second gNodeBfrom the plurality of UEs including the first UE and TOT of downlink RTTreference signals transmitted by the second gNodeB to each of theplurality of UEs, wherein for each UE in the plurality of UEs, thesecond signaling data comprises one of the processing delay between theTOA of the uplink RTT reference signal and the TOT of the downlink RTTreference signal or the total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal; and atleast one memory; and at least one processor coupled to the at least onenetwork interface and the at least one memory and configured toaggregate, for the first UE in the plurality of UEs, the first signalingdata and the second signaling data; and wherein the location of the UEis determined using at least a net RTT between the first UE and each ofthe first gNodeB and the second gNodeB, wherein the net RTT isdetermined using the first signaling data and the second signaling dataaggregated for the first UE.

In one aspect, a network node (location server) in a wireless networkconfigured for determining a location for a first user equipment (UE)using round-trip time (RTT) for signals between the first UE and aplurality of network nodes (gNodeBs), includes means for receiving, froma first gNodeB, a report of first signaling data related to a time ofarrival (TOA) of uplink RTT reference signals received by the firstgNodeB from a plurality of UEs including the first UE and time oftransmission (TOT) of downlink RTT reference signals transmitted by thefirst gNodeB to each of the plurality of UEs, wherein for each UE in theplurality of UEs, the first signaling data comprises one of a processingdelay between the TOA of the uplink RTT reference signal and the TOT ofthe downlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; means for receiving, from a second gNodeB, a report of secondsignaling data related to the TOA of uplink RTT reference signalsreceived by the second gNodeB from the plurality of UEs including thefirst UE and TOT of downlink RTT reference signals transmitted by thesecond gNodeB to each of the plurality of UEs, wherein for each UE inthe plurality of UEs, the second signaling data comprises one of theprocessing delay between the TOA of the uplink RTT reference signal andthe TOT of the downlink RTT reference signal or the total RTT betweenthe TOT of the downlink RTT reference signal and the TOA of the uplinkRTT reference signal; and means for aggregating, for the first UE in theplurality of UEs, the first signaling data and the second signalingdata; and wherein the location of the UE is determined using at least anet RTT between the first UE and each of the first gNodeB and the secondgNodeB, wherein the net RTT is determined using the first signaling dataand the second signaling data aggregated for the first UE.

In one aspect, a non-transitory storage medium including program codestored thereon, the program code is operable to cause at least oneprocessor in a location server to operate for determining location for afirst user equipment (UE) using round-trip time (RTT) for signalsbetween the first UE and a plurality of network nodes (gNodeBs) in awireless network comprising: program code to receive, from a firstgNodeB, a report of first signaling data related to a time of arrival(TOA) of uplink RTT reference signals received by the first gNodeB froma plurality of UEs including the first UE and time of transmission (TOT)of downlink RTT reference signals transmitted by the first gNodeB toeach of the plurality of UEs, wherein for each UE in the plurality ofUEs, the first signaling data comprises one of a processing delaybetween the TOA of the uplink RTT reference signal and the TOT of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; program code to receive, from a second gNodeB, a report ofsecond signaling data related to the TOA of uplink RTT reference signalsreceived by the second gNodeB from the plurality of UEs including thefirst UE and TOT of downlink RTT reference signals transmitted by thesecond gNodeB to each of the plurality of UEs, wherein for each UE inthe plurality of UEs, the second signaling data comprises one of theprocessing delay between the TOA of the uplink RTT reference signal andthe TOT of the downlink RTT reference signal or the total RTT betweenthe TOT of the downlink RTT reference signal and the TOA of the uplinkRTT reference signal; and program code to aggregate, for the first UE inthe plurality of UEs, the first signaling data and the second signalingdata; and wherein the location of the UE is determined using at least anet RTT between the first UE and each of the first gNodeB and the secondgNodeB, wherein the net RTT is determined using the first signaling dataand the second signaling data aggregated for the first UE.

Other objects and advantages associated with the aspects disclosedherein will be apparent to those skilled in the art based on theaccompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are presented to aid in the description ofvarious aspects of the disclosure and are provided solely forillustration of the aspects and not limitation thereof.

FIG. 1 illustrates a high-level system architecture of a wirelesscommunications system in accordance with an aspect of the disclosure.

FIG. 2 illustrates an example configuration of radio access networks(RANs) and a packet-switched portion of a core network that is based onan LTE network in accordance with an aspect of the disclosure.

FIG. 3 is a simplified block diagram of several sample aspects ofcomponents that may be employed in wireless communication nodes andconfigured to support communication as taught herein.

FIG. 4 is diagram illustrating an exemplary technique for determining aposition of a mobile station using information obtained from a pluralityof base stations.

FIGS. 5A and 5B are diagrams showing exemplary timings within a RTToccurring during a wireless probe request and a response.

FIG. 6 illustrates an example of the network-centric RTT estimationaccording to an aspect of the disclosure.

FIG. 7 illustrates an example of the UE-centric RTT estimation accordingto an aspect of the disclosure.

FIG. 8 illustrates an exemplary system in which the RTT estimationprocedures disclosed herein are extended to massive MultipleInput-Multiple Output (MIMO) and millimeter wave (mmW) systems accordingto an aspect of the disclosure.

FIG. 9 illustrates a reference point representation of a communicationsystem based on a 5G NR network, in which RTT estimates may be produced.

FIG. 10 illustrates a call flow of a Mobile Originated Location Request(MO-LR) for RTT measurements for a UE, where the location server is usedto aggregate the measured signal data from the gNodeBs.

FIG. 11 illustrates a call flow of a Mobile Originated Location Request(MO-LR) for RTT measurements for a UE, where a gNodeB is used toaggregate the measured signal data from the gNodeBs.

FIG. 12 illustrates a call flow of a Network Initiated Location Request(NI-LR) for RTT measurements for a UE, where the location server is usedto request the RTT determination and to aggregate the measured signaldata from the gNodeBs.

FIG. 13 illustrates a call flow of a Network Initiated Location Request(NI-LR) for RTT measurements for a UE, where the serving gNodeB is usedto request the RTT determination and the location server is used toaggregate the measured signal data from the gNodeBs.

FIG. 14 illustrates an exemplary method for determining RTT of a UEperformed by a UE according to an aspect of the disclosure.

FIG. 15 illustrates an exemplary method for determining RTT of a UEperformed by a gNodeB according to an aspect of the disclosure.

FIG. 16 illustrates another exemplary method for determining RTT of a UEperformed by a gNodeB according to an aspect of the disclosure

FIG. 17 illustrates an exemplary method for determining RTT of a UEperformed by a location server according to an aspect of the disclosure

FIGS. 18, 19, 20, and 21 are other simplified block diagrams of severalsample aspects of apparatuses configured to support positioning andcommunication as taught herein.

Elements, stages, steps, and/or actions with the same reference label indifferent drawings may correspond to one another (e.g., may be similaror identical to one another). Further, some elements in the variousdrawings are labelled using a numeric prefix followed by an alphabeticor numeric suffix. Elements with the same numeric prefix but differentsuffixes may be different instances of the same type of element. Thenumeric prefix without any suffix is used herein to reference anyelement with this numeric prefix. For example, different instances102-1, 102-2, 102-3, 102-4, 102-5, and 102-N of a UE are shown inFIG. 1. A reference to a UE 102 then refers to any of UEs 102-1, 102-2,102-3, 102-4, 102-5, and 102-N.

DETAILED DESCRIPTION

Disclosed are techniques for calculating a RTT of a UE. In an aspect, agNodeB sends to the UE, one or more downlink RTT measurement signalsduring one or more predefined symbol of a downlink subframe, sends, tothe UE, a command to report an arrival time of each of the one or moredownlink RTT measurement signals, receives, from the UE, a RTT reportcomprising a combination of the arrival time of each of the one or moredownlink RTT measurement signals relative to a downlink subframe timingof the UE and an uplink timing adjust parameter of the UE, andcalculates a RTT between the UE and the gNodeB based on a combination ofthe arrival time of the one or more downlink RTT measurement signals,the timing adjust parameter, and an arrival time of the RTT report atthe gNodeB relative to a system time of the gNodeB.

Also disclosed are techniques for calculating RTT at a UE. In an aspect,the UE receives, from a first gNodeB, a control signal instructing theUE to send an uplink RTT measurement signal during a predefined resourceblock of a subframe, transmits, to one or more gNodeBs, the uplink RTTmeasurement signal during the predefined resource block of the subframe,wherein at least one gNodeB of the one or more gNodeBs measures anarrival time of the uplink RTT measurement signal relative to a downlinksubframe timing of the at least one gNodeB, receives, from the firstgNodeB, an instruction to look for an RTT response from the at least onegNodeB, receives, from the at least one gNodeB, the RTT response, theRTT response including the arrival time of the uplink RTT measurementsignal, and calculates an RTT between the UE and the at least one gNodeBbased on an arrival time of the RTT response, a timing adjust parameter,and the arrival time of the uplink RTT measurement signal relative to adownlink system time of the UE.

These techniques and other aspects are disclosed in the followingdescription and related drawings directed to specific aspects of thedisclosure. Alternate aspects may be devised without departing from thescope of the disclosure. Additionally, well-known elements of thedisclosure will not be described in detail or will be omitted so as notto obscure the relevant details of the disclosure.

The words “exemplary” and/or “example” are used herein to mean “servingas an example, instance, or illustration.” Any aspect described hereinas “exemplary” and/or “example” is not necessarily to be construed aspreferred or advantageous over other aspects. Likewise, the term“aspects of the disclosure” does not require that all aspects of thedisclosure include the discussed feature, advantage or mode ofoperation.

Further, many aspects are described in terms of sequences of actions tobe performed by, for example, elements of a computing device. It will berecognized that various actions described herein can be performed byspecific circuits (e.g., application specific integrated circuits(ASICs)), by program instructions being executed by one or moreprocessors, or by a combination of both. Additionally, the sequence(s)of actions described herein can be considered to be embodied entirelywithin any form of non-transitory computer-readable storage mediumhaving stored therein a corresponding set of computer instructions that,upon execution, would cause or instruct an associated processor of adevice to perform the functionality described herein. Thus, the variousaspects of the disclosure may be embodied in a number of differentforms, all of which have been contemplated to be within the scope of theclaimed subject matter. In addition, for each of the aspects describedherein, the corresponding form of any such aspects may be describedherein as, for example, “logic configured to” perform the describedaction.

A mobile device, also referred to herein as a UE, may be mobile or may(e.g., at certain times) be stationary, and may communicate with a radioaccess network (RAN). As used herein, the term “UE” may be referred tointerchangeably as an “access terminal” or “AT,” a “client device,” a“wireless device,” a “subscriber device,” a “subscriber terminal,” a“subscriber station,” a “user terminal” or UT, a “mobile terminal,” a“mobile station,” or variations thereof. Generally, UEs can communicatewith a core network via a RAN, and through the core network the UEs canbe connected with external networks such as the Internet and with otherUEs. Of course, other mechanisms of connecting to the core networkand/or the Internet are also possible for the UEs, such as over wiredaccess networks, WiFi networks (e.g., based on IEEE 802.11, etc.) and soon. UEs can be embodied by any of a number of types of devices includingbut not limited to printed circuit (PC) cards, compact flash devices,external or internal modems, wireless or wireline phones, smartphones,tablets, tracking devices, asset tags, and so on. A communication linkthrough which UEs can send signals to a RAN is called an uplink channel(e.g., a reverse traffic channel, a reverse control channel, an accesschannel, etc.). A communication link through which the RAN can sendsignals to UEs is called a downlink or forward link channel (e.g., apaging channel, a control channel, a broadcast channel, a forwardtraffic channel, etc.). As used herein the term traffic channel (TCH)can refer to either an uplink/reverse or downlink/forward trafficchannel.

FIG. 1 illustrates a high-level system architecture of a wirelesscommunications system 100 in accordance with an aspect of thedisclosure. The wireless communications system 100 contains UEs 1 to N(referenced as 102-1 to 102-N). The UEs 102-1 to 102-N can includecellular telephones, personal digital assistant (PDAs), pagers, a laptopcomputer, a tablet computer, a desktop computer, and so on. For example,in FIG. 1, UE 102-1 and UE 102-2 are illustrated as cellular featurephones, UEs 102-3, 102-4, and 102-5 are illustrated as cellulartouchscreen phones, or “smartphones,” and UE 102-N is illustrated as adesktop computer, or personal computer (often referred to as a “PC”).Although only six UEs 102 are shown in FIG. 1, the number of UEs 102 inwireless communications system 100 may be in the hundreds, thousands, ormillions (e.g., N may be any number up to or greater than one million).

Referring to FIG. 1, UEs 102-1 to 102-N are configured to communicatewith one or more access networks (e.g., the RANs 120A and 120B, theaccess point 125, etc.) over a physical communications interface orlayer, shown in FIG. 1 as air interfaces 104, 106, and 108 and/or adirect wired connection. The air interfaces 104 and 106 can comply witha given cellular communications protocol (e.g., Code Division MultipleAccess (CDMA), Evolution-Data Optimized (E-VDO), Enhanced High RatePacket Data (eHRPD), Global System for Mobile communications (GSM),Wideband CDMA (W-CDMA), LTE, LTE-U, 5G NR, etc.), while the airinterface 108 can comply with a Wireless Local Area Network (WLAN)protocol (e.g., IEEE 802.11). Both RAN 120A and 120B may include aplurality of access points that serve UEs over air interfaces, such asthe air interfaces 104 and 106. The access points in the RAN 120A and120B can be referred to as access nodes (ANs), access points (APs), basestations (BSs), Node Bs, eNodeBs, gNodeBs, and so on. For example, aneNodeB (also referred to as an evolved NodeB) is typically a basestation that supports wireless access by UEs 102 according to the LTEwireless interface defined by 3GPP. As another example, a gNodeB, orgNB, is typically a base station that supports wireless access by UEs102 according to the 5G NR wireless interface. These access points canbe terrestrial access points (or ground stations), or satellite accesspoints.

Both RANs 120A and 120B are configured to connect to a core network 140that can perform a variety of functions, including routing andconnecting circuit switched (CS) calls between UEs 102 served by the RAN120A/120B and other UEs 102 served by the RAN 120A/120B or UEs served bya different RAN altogether, and can also mediate an exchange ofpacket-switched (PS) data with external networks such as Internet 175and external clients and servers.

The Internet 175 includes a number of routing agents and processingagents (not shown in FIG. 1 for the sake of convenience). In FIG. 1, UE102-N is shown as connecting to the Internet 175 directly (i.e.,separate from the core network 140, such as over an Ethernet connectionof WiFi or 802.11-based network). The Internet 175 can thereby functionto route and connect packet-switched data communications between UE102-N and UEs 102-1 to 102-5 via the core network 140.

Also shown in FIG. 1 is the access point 125 that is separate from theRANs 120A and 120B. The access point 125 may be connected to theInternet 175 independently of the core networks 140 (e.g., via anoptical communication system such as FiOS, a cable modem, etc.). The airinterface 108 may serve UE 102-4 or UE 102-5 over a local wirelessconnection, such as IEEE 802.11 in an example. UE 102-N is shown as adesktop computer with a wired connection to the Internet 175, such as adirect connection to a modem or router, which can correspond to theaccess point 125 itself in an example (e.g., for a WiFi router with bothwired and wireless connectivity).

Referring to FIG. 1, a location server 170 is shown as connected to theInternet 175 and the core network 140. The location server 170 can beimplemented as a plurality of structurally separate servers, oralternately may each correspond to a single server. As will be describedbelow in more detail, the location server 170 is configured to supportone or more location services for UEs 102 that can connect to thelocation server 170 via the core network 140 and/or via the Internet175.

An example of a protocol-specific implementation for the RANs 120A and120B and the core network 140 is provided below with respect to FIG. 2to help explain the wireless communications system 100 in more detail.In particular, the components of the RANs 120A and 120B and the corenetwork 140 correspond to components associated with supportingpacket-switched (PS) communications, whereby legacy circuit-switched(CS) components may also be present in these networks, but any legacyCS-specific components are not shown explicitly in FIG. 2.

FIG. 2 shows an architecture based on a non-roaming 5G NR network tosupport UE positioning using RTT measurements. FIG. 2 illustrates acommunication system 100 that comprises a UE 102, which is sometimesreferred to herein as a “target UE”, since UE 102 may be the target of alocation request. FIG. 2 also shows components of a Fifth Generation(5G) network comprising a Next Generation Radio Access Network (NG-RAN)120A, which includes base stations (BSs) sometimes referred to as NewRadio (NR) NodeBs or gNBs 202, 204, 206, and 208, and a 5G Core Network(SGCN) 140 that is in communication with an external client 250. A 5Gnetwork may also be referred to as a New Radio (NR) network; NG-RAN 120Amay be referred to as an NR RAN or a 5G RAN; and 5GCN 140 may bereferred to as an Next Generation (NG) Core network (NGC). Thecommunication system 100 may further utilize information from spacevehicles (SVs) 190 for a Global Navigation Satellite System (GNSS) likeGPS, GLONASS, Galileo or Beidou or some other local or regionalSatellite Positioning System (SPS) such as IRNSS, EGNOS or WAAS.Additional components of the communication system 100 are describedbelow. The communication system 100 may include additional oralternative components.

FIG. 2 shows a serving gNB 202 for the target UE 102 and neighbor gNBs204, 206, and 208. A neighbor gNB may be any gNB which is able toreceive and measure uplink (UL) signals transmitted by the target UE 102and/or is able to transmit a downlink (DL) reference signal (RS) thatcan be received and measured by the target UE 102.

Entities in the NG-RAN 120A which transmit DL reference signals (RSs) tobe measured by a target UE 102 for a particular location session arereferred to generically as “Transmission Points” (TPs) and can includeone or more of the serving gNB 202, and neighbor gNBs 204, 206, and 208.

Entities in the NG-RAN 120A which receive and measure UL signals (e.g.an RS) transmitted by a target UE 102 for a particular location sessionare referred to generically as “Reception Points” (RPs) and can includeone or more of the serving gNB 202, and neighbor gNBs 204, 206, and 208.

It should be noted that FIG. 2 provides only a generalized illustrationof various components, any or all of which may be utilized asappropriate, and each of which may be duplicated or omitted asnecessary. Specifically, although only one UE 102 is illustrated, itwill be understood that many UEs (e.g., hundreds, thousands, millions,etc.) may utilize the communication system 100. Similarly, thecommunication system 100 may include a larger or smaller number of SVs190, gNBs 202-208, external clients 250, and/or other components. Theillustrated connections that connect the various components in thecommunication system 100 include data and signaling connections whichmay include additional (intermediary) components, direct or indirectphysical and/or wireless connections, and/or additional networks.Furthermore, components may be rearranged, combined, separated,substituted, and/or omitted, depending on desired functionality.

While FIG. 2 illustrates a 5G-based network, similar networkimplementations and configurations may be used for other communicationtechnologies, such as 3G, Long Term Evolution (LTE), and IEEE 802.11WiFi etc. For example, where a Wireless Local Area Network (WLAN), e.g.,IEEE 802.11 radio interface, is used, the UE 102 may communicate with anAccess Network (AN), as opposed to an NG-RAN, and accordingly, component120A is sometimes referred to herein as an AN or as a RAN, denoted bythe term “RAN”, “(R)AN” or “(R)AN 120A”. In the case of an AN (e.g. IEEE802.11 AN), the AN may be connected to a Non-3GPP Interworking Function(N3IWF) (e.g. in SGCN 140) (not shown in FIG. 2), with the N3IWFconnected to AMF 215.

The target UE 102, as used herein, may be any electronic device and maybe referred to as a device, a mobile device, a wireless device, a mobileterminal, a terminal, a mobile station (MS), a Secure User PlaneLocation (SUPL) Enabled Terminal (SET), or by some other name The targetUE 102 may be a stand-alone device or may be embedded in another device,e.g., a factory tool, that is to be monitored or tracked. Moreover, UE102 may correspond to a smart watch, digital glasses, fitness monitor,smart car, smart appliance, cellphone, smartphone, laptop, tablet, PDA,tracking device, control device or some other portable or moveabledevice. The UE 102 may include a single entity or may include multipleentities such as in a personal area network where a user may employaudio, video and/or data I/O devices and/or body sensors and a separatewireline or wireless modem. Typically, though not necessarily, the UE102 may support wireless communication using one or more Radio AccessTechnologies (RATs) such as GSM, Code Division Multiple Access (CDMA),Wideband CDMA (WCDMA), LTE, High Rate Packet Data (HRPD), IEEE 802.11WiFi (also referred to as Wi-Fi), Bluetooth® (BT), WorldwideInteroperability for Microwave Access (WiMAX), 5G new radio (NR) (e.g.,using the NG-RAN 120A and SGCN 140), etc. The UE 102 may also supportwireless communication using a Wireless Local Area Network (WLAN) whichmay connect to other networks (e.g. the Internet) using a DigitalSubscriber Line (DSL) or packet cable for example. The use of one ormore of these RATs may allow the UE 102 to communicate with an externalclient 250 (e.g. via elements of SGCN 140 not shown in FIG. 2, orpossibly via a Gateway Mobile Location Center (GMLC) 220, and/or allowthe external client 250 to receive location information regarding the UE102 (e.g., via the GMLC 220).

The UE 102 may enter a connected state with a wireless communicationnetwork that may include the NG-RAN 120A. In one example, the UE 102 maycommunicate with a cellular communication network by transmittingwireless signals to, or receiving wireless signals from a cellulartransceiver, in the NG-RAN 120A, such as a gNB 202. A transceiverprovides user and control planes protocol terminations toward the UE 102and may be referred to as a base station, a base transceiver station, aradio base station, a radio transceiver, a radio network controller, atransceiver function, a base station subsystem (BSS), an extendedservice set (ESS), or by some other suitable terminology.

In particular implementations, the UE 102 may have circuitry andprocessing resources capable of obtaining location related measurements.Location related measurements obtained by UE 102 may includemeasurements of signals received from satellite vehicles (SVs) 190belonging to a Satellite Positioning System (SPS) or Global NavigationSatellite System (GNSS) such as GPS, GLONASS, Galileo or Beidou and/ormay include measurements of signals received from terrestrialtransmitters fixed at known locations (e.g., such as gNBs). UE 102 orgNB 202 to which UE 102 may send the measurements, may then obtain alocation estimate for the UE 102 based on these location relatedmeasurements using any one of several position methods such as, forexample, GNSS, Assisted GNSS (A-GNSS), Advanced Forward LinkTrilateration (AFLT), Observed Time Difference Of Arrival (OTDOA), WLAN(also referred to as WiFi) positioning, or Enhanced Cell ID (ECID) orcombinations thereof. In some of these techniques (e.g. A-GNSS, AFLT andOTDOA), pseudoranges or timing differences may be measured at UE 102relative to three or more terrestrial transmitters (e.g. gNBs) fixed atknown locations or relative to four or more SVs 190 with accuratelyknown orbital data, or combinations thereof, based at least in part, onpilots, positioning reference signals (PRS) or other positioning relatedsignals transmitted by the transmitters or satellites and received atthe UE 102.

The location server 170 in FIG. 1 may correspond to, e.g., LocationManagement Function (LMF) 225 or Secure User Plane Location (SUPL)Location Platform (SLP) 240, may be capable of providing positioningassistance data to UE 102 including, for example, information regardingsignals to be measured (e.g., expected signal timing, signal coding,signal frequencies, signal Doppler), locations and identities ofterrestrial transmitters (e.g. gNBs) and/or signal, timing and orbitalinformation for GNSS SVs to facilitate positioning techniques such asA-GNSS, AFLT, OTDOA and ECID. The facilitation may include improvingsignal acquisition and measurement accuracy by UE 102 and, in somecases, enabling UE 102 to compute its estimated location based on thelocation measurements. For example, a location server (e.g. LMF 225 orSLP 240) may comprise an almanac, also referred to as a base stationalmanac (BSA), which indicates locations and identities of cellulartransceivers and/or local transceivers in a particular region or regionssuch as a particular venue, and may provide information descriptive ofsignals transmitted by a cellular base station or AP (e.g. a gNB) suchas transmission power and signal timing. A UE 102 may obtainmeasurements of signal strengths (e.g. received signal strengthindication (RSSI)) for signals received from cellular transceiversand/or local transceivers and/or may obtain a signal to noise ratio(S/N), a reference signal received power (RSRP), a reference signalreceived quality (RSRQ), a time of arrival (TOA), an angle of arrival(AOA), an angle of departure (AOD), a receive time-transmission timedifference (Rx-Tx), or a round trip signal propagation time (RTT)between UE 102 and a cellular transceiver (e.g. a gNB) or a localtransceiver (e.g. a WiFi access point (AP)). A UE 102 may use thesemeasurements together with assistance data (e.g. terrestrial almanacdata or GNSS satellite data such as GNSS Almanac and/or GNSS Ephemerisinformation) received from a location server (e.g. LMF 225 or SLP 240)or broadcast by a base station (e.g. a gNB 202-208) in NG-RAN 120A todetermine a location for UE 102.

In some implementations, network entities are used to assist in locationof a target UE 102. For example, entities in a network such as gNBs202-208 may measure UL signals transmitted by UE 102. The UL signals mayinclude or comprise UL reference signals such as UL positioningreference signals (PRSs) or UL Sounding Reference Signals (SRSs). Theentities obtaining the location measurements (e.g. gNBs 202-208) maythen transfer the location measurements to the UE 102, which may use themeasurements to determine RTDs for multiple transceiver pairs. Examplesof UL location measurements can include an RSSI, RSRP, RSRQ, TOA, Rx-Tx,AOA and RTT.

An estimate of a location of the UE 102 may be referred to as alocation, location estimate, location fix, fix, position, positionestimate or position fix, and may be geographic, thus providing locationcoordinates for the UE 102 (e.g., latitude and longitude) which may ormay not include an altitude component (e.g., height above sea level,height above or depth below ground level, floor level or basementlevel). Alternatively, a location of the UE 102 may be expressed as acivic location (e.g., as a postal address or the designation of somepoint or small area in a building such as a particular room or floor). Alocation of the UE 102 may also be expressed as an area or volume(defined either geographically or in civic form) within which the UE 102is expected to be located with some probability or confidence level(e.g., 67%, 95%, etc.). A location of the UE 102 may further be arelative location comprising, for example, a distance and direction orrelative X, Y (and Z) coordinates defined relative to some origin at aknown location which may be defined geographically, in civic terms, orby reference to a point, area, or volume indicated on a map, floor planor building plan. The location may be expressed as an absolute locationestimate for the UE, such as location coordinates or address, or as arelative location estimate for the UE, such as a distance and directionfrom a previous location estimate or from a known absolute location. Thelocation of the UE may include a linear velocity, an angular velocity, alinear acceleration, an angular acceleration, an angular orientation forthe UE, e.g., the orientation of the UE relative to a fixed global orlocal coordinate system, an identification of a trigger event forlocating the UE, or some combination of these. For example, triggerevents may include an area event, a motion event or a velocity event. Anarea event, for example, may be the UE moving into a defined area,moving out of the area and/or remaining in the area. A motion event, forexample, may include movement of the UE by a threshold straight linedistance or threshold distance along a UE trajectory. A velocity event,for example, may include the UE attaining a minimum or maximum velocity,a threshold increase and/or decrease of velocity, and/or a thresholdchange in direction. In the description contained herein, the use of theterm location may comprise any of these variants unless indicatedotherwise. When computing the location of a UE, it is common to solvefor local x, y, and possibly z coordinates and then, if needed, convertthe local coordinates into absolute ones (e.g. for latitude, longitudeand altitude above or below mean sea level).

As shown in FIG. 2, pairs of gNBs in NG-RAN 120A may be connected to oneanother, e.g., directly as shown in FIG. 2 or indirectly via other gNBs202-208. Access to the 5G network is provided to UE 102 via wirelesscommunication between the UE 102 and one or more of the gNBs 202-208,which may provide wireless communication access to the SGCN 140 onbehalf of the UE 102 using 5G (e.g. NR). In FIG. 2, the serving gNB forUE 102 is assumed to be gNB 202, although other gNBs (e.g. gNB 204, 206,or 208) may act as a serving gNB if UE 102 moves to another location ormay act as a secondary gNB to provide additional throughout andbandwidth to UE 102. Some gNBs in FIG. 2 (e.g. gNB 204, 206, or 208) maybe configured to function as positioning-only beacons which may transmitsignals (e.g. directional PRS) to assist positioning of UE 102 but maynot receive signals from UE 102 or from other UEs.

As noted, while FIG. 2 depicts nodes configured to communicate accordingto 5G communication protocols, nodes configured to communicate accordingto other communication protocols, such as, for example, LTE protocols,may be used. Such nodes, configured to communicate using differentprotocols, may be controlled, at least in part, by the SGCN 140. Thus,the NG-RAN 120A may include any combination of gNBs, evolved Node Bs(eNBs) supporting LTE, or other types of base stations or access points.As an example, NG-RAN 120A may include one or more next generation eNBs(ng-eNBs), not shown, which provide LTE wireless access to UE 102 andmay connect to entities in SGCN 140 such as AMF 215.

The gNBs 202, 204, 206, and 208 can communicate with the Access andMobility Management Function (AMF) 215, which, for positioningfunctionality, may communicate with a Location Management Function (LMF)225. The AMF 215 may support mobility of the UE 102, including cellchange and handover and may participate in supporting a signalingconnection to the UE 102 and possibly helping establish and releaseProtocol Data Unit (PDU) sessions for UE 102 supported by the UPF 230.Other functions of AMF 215 may include: termination of a control plane(CP) interface from NG-RAN 120A; termination of Non-Access Stratum (NAS)signaling connections from UEs such as UE 102, NAS ciphering andintegrity protection; registration management; connection management;reachability management; mobility management; access authentication andauthorization.

The gNB 202 may support positioning of the UE 102 when UE 102 accessesthe NG-RAN 120A. The gNB 202 may also process location service requestsfor the UE 102, e.g., received directly or indirectly from the GMLC 220.In some embodiments, a node/system that implements the gNB 202 mayadditionally or alternatively implement other types of location-supportmodules, such as an Enhanced Serving Mobile Location Center (E-SMLC) ora Secure User Plane Location (SUPL) Location Platform (SLP) 240. It willbe noted that in some embodiments, at least part of the positioningfunctionality (including derivation of UE 102's location) may beperformed at the UE 102 (e.g., using signal measurements for signalstransmitted by wireless nodes, and assistance data provided to the UE102).

The GMLC 220 may support a location request for the UE 102 received froman external client 250 and may forward such a location request to aserving AMF 215 for UE 102. The AMF 215 may then forward the locationrequest to either gNB 202 or LMF 225 which may obtain one or morelocation estimates for UE 102 (e.g. according to the request fromexternal client 250) and may return the location estimate(s) to AMF 215,which may return the location estimate(s) to external client 250 viaGMLC 220. GMLC 220 may contain subscription information for an externalclient 250 and may authenticate and authorize a location request for UE102 from external client 250. GMLC 220 may further initiate a locationsession for UE 102 by sending a location request for UE 102 to AMF 215and may include in the location request an identity for UE 102 and thetype of location being requested (e.g. such as a current location or asequence of periodic or triggered locations).

As further illustrated in FIG. 2, an external client 250 may beconnected to the core network 140 via the GMLC 220 and/or the SLP 240.The external client 250 may optionally be connected to the core network140 and/or to an SLP 260, that is external to SGCN 140, via the Internet175. The external client 250 may be a server, a web server, or a userdevice, such as a personal computer, a UE, etc.

The LMF 225 and the gNB 202 may communicate using a New Radio PositionProtocol A (which may be referred to as NPPa or NRPPa). NRPPa may bedefined in 3GPP TS 38.455, with NRPPa messages being transferred betweenthe gNB 202 and the LMF 225. Further, the LMF 225 and UE 102 maycommunicate using the LTE Positioning Protocol (LPP) defined in 3GPP TS36.355, where LPP messages are transferred between the UE 102 and theLMF 225 via the serving AMF 215 and the serving gNB 202 for UE 102. Forexample, LPP messages may be transferred between the AMF 215 and the UE102 using a 5G Non-Access Stratum (NAS) protocol. The LPP protocol maybe used to support positioning of UE 102 using UE assisted and/or UEbased position methods such as Assisted GNSS (A-GNSS), Real TimeKinematics (RTK), Wireless Local Area Network (WLAN), Observed TimeDifference of Arrival (OTDOA), Round-Trip Time (RTT), and/or EnhancedCell Identity (ECID). The NRPPa protocol may be used to supportpositioning of UE 102 using network based position methods such as ECID(when used with measurements obtained by or received from a gNB 202,204, 206, or 208) and/or may be used by LMF 225 to obtain locationrelated information from gNBs such as parameters defining positioningreference signal (PRS) transmission from gNBs for support of OTDOA.

GNBs 202, 204, 206, or 208 may communicate with AMF 215 using a NextGeneration Application Protocol (NGAP), e.g. as defined in 3GPPTechnical Specification (TS) 38.413, or using a location specificprotocol (referred to here as LSP1) transported by NGAP. NGAP or theLSP1 may enable AMF 215 to request a location of a target UE 102 from agNB 202 for target UE 102 and may enable gNB 202 to return a locationfor UE 102 to the AMF 215.

GNBs 202, 204, 206, or 208 may communicate with one another using an XnApplication Protocol (XnAP), e.g. as defined in 3GPP TS 38.423, or usinga location specific protocol (referred to here as LSP2) transported byXnAP, which may be different to LSP1. XnAP or LSP2 may allow one gNB torequest another gNB to obtain UL location measurements for a target UEand to return the UL location measurements. XnAP or LSP2 may also enablea gNB to request another gNB to transmit a downlink (DL) RS or PRS toenable a target UE 102 to obtain DL location measurements of thetransmitted DL RS or PRS. In some embodiments, LSP2 (when used) may besame as or an extension to NRPPa.

A gNB (e.g. gNB 202) may communicate with a target UE 102 using a RadioResource Control (RRC) protocol, e.g. as defined in 3GPP TS 38.331, orusing a location specific protocol (referred to here as LSP3)transported by RRC, which may be different to LSP1 and LSP2. RRC or LSP3may allow a gNB (e.g. gNB 202) to request location measurements from thetarget UE 102 of DL RSs or DL PRSs transmitted by the gNB 202 and/or byother gNBs 204, 206, or 208 and to return some or all of the locationmeasurements. RRC or LSP3 may also enable a gNB (e.g. gNB 202) torequest the target UE 102 to transmit an UL RS or PRS to enable the gNB202 or other gNBs 204, 206, or 208 to obtain UL location measurements ofthe transmitted UL RS or PRS. In some embodiments, LSP3 (when used) maybe same as or an extension to LPP.

With a UE assisted position method, UE 102 may obtain locationmeasurements (e.g. measurements of RSSI, Rx-Tx, RTT, RSTD, RSRP and/orRSRQ for gNBs 202, 204, 206, or 208 or WLAN APs, or measurements of GNSSpseudorange, code phase and/or carrier phase for SVs 190) and send themeasurements to an entity performing a location server function, e.g.,LMF 225, or SLP 240, for computation of a location estimate for UE 102.With a UE based position method, UE 102 may obtain location measurements(e.g. which may be the same as or similar to location measurements for aUE assisted position method) and may compute a location of UE 102 (e.g.with the help of assistance data received from a location server such asLMF 225 or SLP 240). With a network based position method, one or morebase stations (e.g. gNBs 202-208) or APs may obtain locationmeasurements (e.g. measurements of RSSI, RTT, RSRP, RSRQ, Rx-Tx or TOAfor signals transmitted by UE 102) and/or may receive measurementsobtained by UE 102, and may send the measurements to a location server,e.g., LMF 225, for computation of a location estimate for UE 102.

Information provided by the gNBs 204, 206, or 208 to the gNB 202 usingXnAP or LSP2 may include timing and configuration information for PRStransmission and location coordinates of the gNBs 204, 206, or 208. ThegNB 202 can then provide some or all of this information to the UE 102as assistance data in an RRC or LSP3 message. An RRC message sent fromgNB 202 to UE 102 may include an embedded LSP3 message (e.g. an LPPmessage) in some implementations.

An RRC or LSP3 message sent from the gNB 202 to the UE 102 may instructthe UE 102 to do any of a variety of things, depending on desiredfunctionality. For example, the RRC or LSP3 message could contain aninstruction for the UE 102 to obtain measurements for GNSS (or A-GNSS),WLAN, and/or OTDOA (or some other position method) or to transmit uplink(UL) signals, such as Positioning Reference Signals, Sounding ReferenceSignals, or both. In the case of OTDOA, the RRC or LSP3 message mayinstruct the UE 102 to obtain one or more measurements (e.g. RSTDmeasurements) of PRS signals transmitted within particular cellssupported by particular gNBs. The UE 102 may use the measurements todetermine the position of UE 102, e.g., using OTDOA.

In some embodiments, LPP may be augmented by or replaced by an NR or NGpositioning protocol (NPP or NRPP) which supports position methods suchas OTDOA and ECID for NR radio access. For example, an LPP message maycontain an embedded NPP message or may be replaced by an NPP message.

A gNB in NG-RAN 120A may also broadcast positioning assistance data toUEs such as UE 102.

As illustrated, a Session Management Function (SMF) 235 connects the AMF215 and the UPF 230. The SMF 235 may have the capability to control botha local and a central UPF within a PDU session. SMF 235 may manage theestablishment, modification and release of PDU sessions for UE 102,perform IP address allocation and management for UE 102, act as aDynamic Host Configuration Protocol (DHCP) server for UE 102, and selectand control a UPF 230 on behalf of UE 102.

The User Plane Function (UPF) 230 may support voice and data bearers forUE 102 and may enable UE 102 voice and data access to other networkssuch as the Internet 175. UPF 230 functions may include: external PDUsession point of interconnect to a Data Network, packet (e.g. InternetProtocol (IP)) routing and forwarding, packet inspection and user planepart of policy rule enforcement, Quality of Service (QoS) handling foruser plane, downlink packet buffering and downlink data notificationtriggering. UPF 230 may be connected to SLP 240 to enable support oflocation of UE 102 using SUPL. SLP 240 may be further connected to oraccessible from external client 250.

It should be understood that while FIG. 2 shows a network architecturefor a non-roaming UE, with suitable, well-known, changes, acorresponding network architecture may be provided for a roaming UE.

Time intervals of a communications resource in LTE or 5G NR may beorganized according to radio frames each having a duration of 10milliseconds (ms). The radio frames may be identified by a system framenumber (SFN) ranging from 0 to 1023. Each frame may include 10 subframesnumbered from 0 to 9, and each subframe may have a duration of 1 ms. Asubframe may be further divided into 2 slots each having a duration of0.5 ms, and each slot may contain 6 or 7 modulation symbol periods(e.g., depending on the length of the cyclic prefix prepended to eachsymbol period). In some cases, a subframe may be the smallest schedulingunit of the wireless communications system 100, and may be referred toas a transmission time interval (TTI). In other cases, a smallestscheduling unit of the wireless communications system 100 may be shorterthan a subframe or may be dynamically selected (e.g., in bursts ofshortened TTIs (sTTIs) or in selected component carriers using sTTIs).

FIG. 3 illustrates several sample components (represented bycorresponding blocks) that may be incorporated into an apparatus 302, anapparatus 304, and an apparatus 306 (corresponding to, for example, aUE, a base station (e.g., an gNodeB), and a network entity or locationserver, respectively) to support the operations as disclosed herein. Asan example, the apparatus 302 may correspond to a UE 102, the apparatus304 may correspond to any of gNodeBs 202-206, and the apparatus 306 maycorrespond to the LMF 225, SLP 240, SLP 260, or GMLC 220. It will beappreciated that the components may be implemented in different types ofapparatuses in different implementations (e.g., in an ASIC, in an SoC,etc.). The illustrated components may also be incorporated into otherapparatuses in a communication system. For example, other apparatuses ina system may include components similar to those described to providesimilar functionality. Also, a given apparatus may contain one or moreof the components. For example, an apparatus may include multipletransceiver components that enable the apparatus to operate on multiplecarriers and/or communicate via different technologies.

The apparatus 302 and the apparatus 304 each include at least onewireless communication device (represented by the communication devices308 and 314) for communicating with other nodes via at least onedesignated radio access technology (RAT) (e.g., LTE, 5G NR). Eachcommunication device 308 includes at least one transmitter (representedby the transmitter 310) for transmitting and encoding signals (e.g.,messages, indications, information, and so on) and at least one receiver(represented by the receiver 312) for receiving and decoding signals(e.g., messages, indications, information, pilots, and so on). Eachcommunication device 314 includes at least one transmitter (representedby the transmitter 316) for transmitting signals (e.g., messages,indications, information, pilots, and so on) and at least one receiver(represented by the receiver 318) for receiving signals (e.g., messages,indications, information, and so on).

A transmitter and a receiver may comprise an integrated device (e.g.,embodied as a transmitter circuit and a receiver circuit of a singlecommunication device) in some implementations, may comprise a separatetransmitter device and a separate receiver device in someimplementations, or may be embodied in other ways in otherimplementations. A wireless communication device (e.g., one of multiplewireless communication devices) of the apparatus 304 may also comprise aNetwork Listen Module (NLM) or the like for performing variousmeasurements.

The apparatus 304 and the apparatus 306 include at least onecommunication device (represented by the communication device 320 andthe communication device 326) for communicating with other nodes. Forexample, the communication device 326 may comprise a network interface(e.g., one or more network access ports) that is configured tocommunicate with one or more network entities via a wire-based orwireless backhaul connection. In some aspects, the communication device326 may be implemented as a transceiver configured to support wire-basedor wireless signal communication. This communication may involve, forexample, sending and receiving: messages, parameters, or other types ofinformation. Accordingly, in the example of FIG. 3, the communicationdevice 326 is shown as comprising a transmitter 328 and a receiver 330(e.g., network access ports for transmitting and receiving). Similarly,the communication device 320 may comprise a network interface that isconfigured to communicate with one or more network entities via awire-based or wireless backhaul. As with the communication device 326,the communication device 320 is shown as comprising a transmitter 322and a receiver 324.

The apparatuses 302, 304, and 306 also include other components that maybe used in conjunction with the operations as disclosed herein. Theapparatus 302 includes a processing system 332 for providingfunctionality relating to, for example, RTT measurements in a licensedor unlicensed frequency band as disclosed herein and for providing otherprocessing functionality. The apparatus 304 includes a processing system334 for providing functionality relating to, for example, RTTmeasurements in a licensed or unlicensed frequency band as disclosedherein and for providing other processing functionality. The apparatus306 includes a processing system 336 for providing functionalityrelating to, for example, RTT measurements in a licensed or unlicensedfrequency band as disclosed herein and for providing other processingfunctionality. In an aspect, the processing systems 332, 334, and 336may include, for example, one or more general purpose processors,multi-core processors, application-specific integrated circuits (ASICs),digital signal processors (DSPs), field programmable gate arrays (FPGA),or other programmable logic devices or processing circuitry.

The apparatuses 302, 304, and 306 include memory components 338, 340,and 342 (e.g., each including a memory device), respectively, formaintaining information (e.g., information indicative of reservedresources, thresholds, parameters, and so on). In addition, theapparatuses 302, 304, and 306 include user interface devices 344, 346,and 348, respectively, for providing indications (e.g., audible and/orvisual indications) to a user and/or for receiving user input (e.g.,upon user actuation of a sensing device such a keypad, a touch screen, amicrophone, and so on).

For convenience, the apparatuses 302, 304, and/or 306 are shown in FIG.3 as including various components that may be configured according tothe various examples described herein. It will be appreciated, however,that the illustrated blocks may have different functionality indifferent designs.

The components of FIG. 3 may be implemented in various ways. In someimplementations, the components of FIG. 3 may be implemented in one ormore circuits such as, for example, one or more processors and/or one ormore ASICs (which may include one or more processors). Here, eachcircuit may use and/or incorporate at least one memory component forstoring information or executable code used by the circuit to providethis functionality. For example, some or all of the functionalityrepresented by blocks 308, 332, 338, and 344 may be implemented byprocessor and memory component(s) of the apparatus 302 (e.g., byexecution of appropriate code and/or by appropriate configuration ofprocessor components). Similarly, some or all of the functionalityrepresented by blocks 314, 320, 334, 340, and 346 may be implemented byprocessor and memory component(s) of the apparatus 304 (e.g., byexecution of appropriate code and/or by appropriate configuration ofprocessor components). Also, some or all of the functionalityrepresented by blocks 326, 336, 342, and 348 may be implemented byprocessor and memory component(s) of the apparatus 306 (e.g., byexecution of appropriate code and/or by appropriate configuration ofprocessor components).

In an aspect, the apparatus 304 may correspond to a “small cell” or aHome gNodeB, such as Home gNodeB 202 in FIG. 2. The apparatus 302 maytransmit and receive messages via a wireless link 360 with the apparatus304, the messages including information related to various types ofcommunication (e.g., voice, data, multimedia services, associatedcontrol signaling, etc.). The wireless link 360 may operate over acommunication medium of interest, shown by way of example in FIG. 3 asthe medium 362, which may be shared with other communications as well asother RATs. A medium of this type may be composed of one or morefrequency, time, and/or space communication resources (e.g.,encompassing one or more channels across one or more carriers)associated with communication between one or more transmitter/receiverpairs, such as the apparatus 304 and the apparatus 302 for the medium362.

As a particular example, the medium 362 may correspond to at least aportion of an unlicensed frequency band shared with (an)other RAN and/orother APs and UEs. In general, the apparatus 302 and the apparatus 304may operate via the wireless link 360 according to one or more radioaccess types, such as LTE, LTE-U, or 5G NR, depending on the network inwhich they are deployed. These networks may include, for example,different variants of CDMA networks (e.g., LTE networks, 5G NR networks,etc.), Time Division Multiple Access (TDMA) networks, Frequency DivisionMultiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks,Single-Carrier FDMA (SC-FDMA) networks, and so on. Although differentlicensed frequency bands have been reserved for wireless communications(e.g., by a government entity such as the Federal CommunicationsCommission (FCC) in the United States), certain communication networks,in particular those employing small cell base stations, have extendedoperation into unlicensed frequency bands, such as the UnlicensedNational Information Infrastructure (U-NII) band used by Wireless LocalArea Network (WLAN) technologies, most notably IEEE 802.11x WLANtechnologies generally referred to as “Wi-Fi,” and LTE in unlicensedspectrum technologies generally referred to as “LTE-U” or “MuLTEFire.”

Apparatus 302 may also include an RTT measurement component 352 that maybe used to obtain location related measurements of signals (e.g., RTT orother signals) transmitted by a base station or AP (e.g., any of gNodeBs202-206) according to techniques described herein. Location relatedmeasurements may include measurements of signal propagation time or RTTbetween a UE 102 and a base station or AP, such as any of gNodeBs202-206.

Apparatus 304 and 306 may each include an RTT measurement component 354and 356, respectively, which may be used to determine a locationestimate for a UE 102 (e.g., apparatus 302), according to techniquesdescribed herein, based on location related measurements provided by theUE 102 and/or by a base station or AP, such as any of gNodeBs 202-206.Location related measurements obtained by the UE 102 may includemeasurements of signal propagation time or RTT between a UE 102 and abase station or AP, such as any of gNodeBs 202-206. Location relatedmeasurements obtained by any of gNodeBs 202-206 (e.g., apparatus 304)may include measurements of signal propagation time or RTT between theUE 102 and a base station or AP, such as any of gNodeBs 202-206.

A simplified environment is shown in FIG. 4 for illustrating anexemplary technique for determining a position of UE 102. The UE 102 maycommunicate wirelessly with a plurality of gNodeBs 202-206 using radiofrequency (RF) signals and standardized protocols for the modulation ofthe RF signals and the exchanging of information packets. By extractingdifferent types of information from the exchanged signals, and utilizingthe layout of the network (i.e., the network geometry) the UE 102 maydetermine its position in a predefined reference coordinate system. Asshown in FIG. 4, the UE 102 may specify its position (x, y) using atwo-dimensional coordinate system; however, the aspects disclosed hereinare not so limited, and may also be applicable to determining positionsusing a three-dimensional coordinate system, if the extra dimension isdesired. Additionally, while three gNodeBs 202-206 are shown in FIG. 4,aspects may utilize additional gNodeBs.

In order to determine its position (x, y), the UE 102 may first need todetermine the network geometry. The network geometry can include thepositions of each of the gNodeBs 202-206 in a reference coordinatesystem ((x_(k), y_(k)), where k=1, 2, 3). The network geometry may beprovided to the UE 102 in any manner, such as, for example, providingthis information in beacon signals, providing the information using adedicated server external on an external network, providing theinformation using uniform resource identifiers, etc.

The UE 102 may then determine a distance (d_(k), where k=1, 2, 3) toeach of the gNodeBs 202-206. As will be described in more detail below,there are a number of different approaches for estimating thesedistances (d_(k)) by exploiting different characteristics of the RFsignals exchanged between the UE 102 and gNodeBs 202-206. Suchcharacteristics may include, as will be discussed below, the round trippropagation time of the signals, and/or the strength of the signals(RSSI).

In other aspects, the distances (d_(k)) may in part be determined orrefined using other sources of information that are not associated withthe gNodeBs 202-206. For example, other positioning systems, such asGPS, may be used to provide a rough estimate of d_(k). (Note that it islikely that GPS may have insufficient signal in the anticipatedoperating environments (indoors, metropolitan, etc.) to provide aconsistently accurate estimate of d_(k). However GPS signals may becombined with other information to assist in the position determinationprocess.) Other relative positioning devices may reside in the UE 102which can be used as a basis to provide rough estimates of relativeposition and/or direction (e.g., on-board accelerometers).

Once each distance is determined, the UE 102 can then solve for itsposition (x, y) by using a variety of known geometric techniques, suchas, for example, trilateration. From FIG. 4, it can be seen that theposition of the UE 102 ideally lies at the intersection of the circlesdrawn using dotted lines. Each circle being defined by radius d_(k) andcenter (x_(k), y_(k)), where k=1, 2, 3. In practice, the intersection ofthese circles may not lie at a single point due to the noise and othererrors in the networking system.

Determining the distance between the UE 102 and each gNodeB 202-206 mayinvolve exploiting time information of the RF signals. In an aspect,determining the RTT of signals exchanged between the UE 102 and a gNodeB202-206 can be performed and converted to a distance (d_(k)). RTTtechniques can measure the time between sending a data packet andreceiving a response. These methods utilize calibration to remove anyprocessing delays. In some environments, it may be assumed that theprocessing delays for the UE 102 and the gNodeBs 202-206 are the same.However, such an assumption may not be true in practice.

A position estimate (e.g., for a UE 102) may be referred to by othernames, such as a location estimate, location, position, position fix,fix, or the like. A position estimate may be geodetic and comprisecoordinates (e.g., latitude, longitude, and possibly altitude) or may becivic and comprise a street address, postal address, or some otherverbal description of a location. A position estimate may further bedefined relative to some other known location or defined in absoluteterms (e.g., using latitude, longitude, and possibly altitude). Aposition estimate may include an expected error or uncertainty (e.g., byincluding an area or volume within which the location is expected to beincluded with some specified or default level of confidence).

FIGS. 5A and 5B are diagrams showing exemplary timings within an RTToccurring during a wireless probe request and a response initiated by aUE and a gNodeB, respectively. In an aspect, the response may take theform of an acknowledgement packet (ACK); however, any type of responsepacket would be consistent with various aspects of the disclosure. Forexample, an RTS (request to send) transmit packet and/or CTS (clear tosend) response packet may be suitable.

As illustrated in FIG. 5A, to measure the RTT with respect to a givengNodeB (e.g., any of gNodeBs 202-206), the UE 102 may send a directedprobe request, e.g., an uplink RTT reference signal, to gNodeB, andrecord the time (timestamp) the probe request packet was sent (t_(TX)Packet) as shown on the UE timeline. After a propagation time t_(P) fromthe UE 102 to the gNodeB, the gNodeB will receive the packet. The gNodeBmay then process the directed probe request and may send an ACK back,e.g., a downlink RTT reference signal, to the UE 102 after someprocessing time A, sometimes referred to herein as a processing delay,as shown on the gNodeB timeline in FIG. 5A. After a second propagationtime t_(P), the UE 102 may record the time (timestamp) the ACK packetwas received (t_(RX) ACK) as shown on the UE time line. The UE 102, orother entity, such as the location server, may then determine the totalRTT as the time difference t_(RX) ACK−t_(TX) Packet. The net RTT, i.e.,the two-way propagation time, may be determined based on the differencebetween the total RTT and the processing delay Δ.

FIG. 5B, is similar to FIG. 5A, but illustrates that to measure the RTTwith respect to a UE, a gNodeB (e.g., any of gNodeBs 202-206) may send adirected probe request, e.g., a downlink RTT reference signal, to theUE, and record the time (timestamp) the probe request packet was sent(t_(TX) Packet) as shown on the gNB timeline. After a propagation timet_(P) from the gNodeB to the UE 102, the UE 102 will receive the packet.The UE 102 may then process the directed probe request and may send anACK, e.g., an uplink RTT reference signal, back to the gNodeB after someprocessing time A, e.g., the processing delay, as shown on the UEtimeline in FIG. 5B. After a second propagation time t_(p), the gNodeBmay record the time (timestamp) the ACK packet was received (t_(RX) ACK)as shown on the gNB time line. The gNodeB, or other entity such as theUE 102 or location server, may then determine the net RTT as the timedifference t_(RX) ACK−t_(TX) Packet. The net RTT, i.e., the two-waypropagation time, may be determined based on the difference between thetotal RTT and the processing delay Δ.

Position location methods, such as observed time difference of arrival(OTDOA), currently used in cellular networks require fine (e.g.,sub-microsecond) synchronization of timing across base-stations in thenetwork. On the other hand, RTT-based methods only need coarse timingsynchronization (within a cyclic prefix (CP) duration of the orthogonalfrequency-division multiplexing (OFDM) symbols). The present disclosuredescribes procedures that can be implemented in a 5G NR network,exploiting its self-contained subframe structure.

In 5G NR, there is no requirement for precise timing synchronizationacross the network. Instead, it is sufficient to have (coarse) CP-leveltime-synchronization across gNodeBs. Coarse time-synchronization enableslow-reuse of RTT Measurement signals, which mitigates intercellinterference. Intercell interference mitigation ensures deep penetrationof RTT signals, which enables multiple independent timing measurementsacross distinct gNBs, and hence more accurate positioning.

In a network-centric RTT estimation, the serving gNodeB (one of gNodeBs202-206) instructs the UE (e.g., UE 102) to look for RTT signals fromone or more gNodeBs (one of more of gNodeBs 202-206). The one of moregNodeBs transmit RTT Measurement signals on low reuse resources,allocated by the network (e.g., location server 170). The UE records thearrival times Δt(i) of each RTT Measurement signal, relative to itscurrent DL timing, and transmits a common or individual RTT Responsemessage(s) to the one or more gNodeBs (when instructed by its servinggNodeB). The RTT Response message directed at a particular gNodeBincludes, in its payload, the timestamp(s) (Δt(i)+TA), where Δt(i)denotes the arrival time of the RTT Measurement signal received fromthat gNB and TA denotes the uplink timing-adjust parameter of the UE. Inthe case of a common RTT Response message, the set of time-stamps(Δni)+TA) may be re-organized in other ways, well-known to a person ofordinary skill in the art. The network may allocate low reuse resourcesfor the UE to transmit the RTT Response message(s). In any case, eachgNodeB that receives an RTT Response message records its arrival timeΔT(i), relative to the DL time-reference of the gNodeB. The gNodeB cancompute RTT between the UE and itself by adding the timestamp value(Δt(i)+TA) to the arrival time ΔT(i). This computation may be performedeither at the gNodeBs receiving of the RTT Response signal from the UE,or at a central location in the network.

FIG. 6 illustrates an example of the network-centric RTT estimationaccording to an aspect of the disclosure. As shown in FIG. 6, on adownlink-centric/downlink-only subframe (at low duty-cycle) of thedownlink (DL) sequence of subframes 602, the serving gNodeB sends acontrol signal (e.g., on the physical downlink control channel (PDCCH))to the UE 102, indicating to the UE 102 that one or more gNodeBs(gNodeBs 202-206 in the example of FIG. 6) will be transmitting downlinkRTT Measurement (RTTM) signal(s). During the downlink sequences ofsubframes 606 and 608, gNodeBs 202-206 transmit downlink RTT Measurementsignals at specified symbols of the subframe, in a time divisionmultiplexing (TDM) or frequency division multiplexing (FDM) fashion. TheRTT Measurements transmitted by the gNodeBs 202-206 should be widebandsignals to enable the UE 102 to make precise timing measurements. Noother signals should be transmitted in or around the symbols associatedwith the RTT Measurements by any other gNodeB in the neighborhood(resulting in low-reuse, interference avoidance, and deep penetration ofRTT Measurements).

During downlink the sequence of subframes 604, the UE 102 measures thearrival time Δt(i) of each downlink RTT Measurement transmitted duringthe sequences of subframes 606 and 608 relative to its own downlinksubframe timing (derived from the downlink signal received from theserving gNodeB on the PDCCH). The UE 102 is instructed to report its RTTMeasurements on the physical uplink shared channel (PUSCH) during asubsequent subframe, which it does during the uplink sequence ofsubframes 612. The report from the UE 102 includes the arrival timesΔt(i) of each downlink RTT Measurement, as well as the UE 102's ownuplink timing-adjust (TA) provided by the serving gNodeB. Like thedownlink RTT Measurements transmitted by the gNodeBs 202-206, the uplinkRTT Measurements transmitted by the UE 102 should be wideband signals toenable the gNodeBs to make precise timing measurements.

Each gNodeB in the UE 102's neighborhood (i.e., within communicationrange of the UE 102; gNodeBs 202-206 in the example of FIG. 6) receivesthe report from the UE 102 during the uplink sequence of subframes 614and decodes it, and also records the arrival time ΔT(i) of the uplink(UL) signals from the UE 102, relative to its own system-time. The RTTmay then be computed from the arrival time of the report from the UE102, combined with timing information in the payload (i.e., the RTTMeasurement report).

Note that the TA, which should also be a wideband signal, is a parameterthat accounts for the UE 102's distance from the serving gNodeB. The TAenables all uplink signals from the UE 102 to arrive at the servinggNodeB at the same time. The uplink TA enables the RTT Measurements toarrive exactly at the end of the gap.

A UE-centric RTT estimation is similar to the network-based method,except that the UE (e.g., UE 102) transmits RTT Measurement signal(s)(when instructed), which are received by multiple gNodeBs in theneighborhood of UE. Each gNodeB responds with a RTT Response message,including the arrival time Δt(i) of the RTT Measurement signal from theUE in the message payload. The UE determines the arrival time ΔT(i) ofthe RTT Measurement message, decodes the RTT Response message andestimates, extracts the time-stamp Δt(i) embedded in the message, andcomputes the RTT for the responding gNodeB, by adding the measuredarrival-time ΔT(i), the extracted time-stamp Δt(i), and its ownuplink-downlink timing-adjust value TA.

FIG. 7 illustrates an example of the UE-centric RTT estimation accordingto an aspect of the disclosure. On an uplink-centric (at low duty-cycle)subframe during the uplink sequence of subframes 702, the serving gNodeBsends a control signal (e.g., on the PDCCH) to the UE 102, instructingthe UE 102 (and any number of other UEs) to transmit an uplink RTTMeasurement signal (UL-RTTM).

During the uplink sequence of subframes 704, the UE 102 transmits an RTTMeasurement signal at specified resource blocks of the uplink dataportion of the subframe, in a TDM or FUM fashion. The RTT Measurementsignals should be wideband signals to enable more precise timingmeasurements. No other signals should be transmitted on the symbolsassociated with the uplink RTT Measurement signals by any UE in theneighborhood (resulting in low reuse, interference avoidance, and deeppenetration of RTTM).

During the uplink sequences of subframes 706 and 708, each gNodeB in theneighborhood (i.e., within communication range of the UE 102; gNodeBs202-206 in the example of FIG. 7) measures the arrival time Δt(i) ofeach uplink RTT Measurement signal relative to its own downlinksub-frame timing (assuming a synchronous deployment of the gNodeBs). Theserving gNodeB instructs the UE 102 to look for RTT Responses from thegNodeBs 202-206 on a subsequent subframe, which occurs during thedownlink sequences of subframes 714 and 716. The RTT Response signalfrom each gNodeB 202-206 includes the arrival times Δt(i) of the uplinkRTT Measurement signal from the UE 102. The RTT Response signals shouldbe wideband signals to enable the UE 102 to make precise timingmeasurements.

The UE 102, and each UE in the neighborhood (e.g., all UEs withincommunication range of the serving gNodeB and gNodeBs 202-206), decodesthe RTT Responses from the gNodeBs 202-206 during the downlink sequenceof subframes 712, and also measures the arrival time ΔT(i) of the uplinksignals from the gNodeBs 202-206, relative to its own (downlink)system-time.

The RTT may be computed from the arrival time of the downlink RTTResponse at the UE 102, combined with timing information in the gNodeBpayload (downlink RTT Response), along with its own TA (provided by theserving gNodeB). Any mismatch between inter-gNodeB timing may beabsorbed into 0.5 RTT(0); there is no requirement for precise timingsynchronization across the gNodeBs 202-206.

The RTT estimation procedures disclosed herein can be extended tomassive Multiple Input-Multiple Output (MIMO) and to extremely-highfrequency (EHF) region of the spectrum, also known as millimeter wave(mmW) (generally, spectrum bands above 24 GHz) systems. In mmW bandsystems, as well as massive MIMO systems in any band, gNodeBs usetransmission/reception beamforming to extend signal coverage to the celledge.

“Beamforming” is a technique for focusing an RF signal in a specificdirection. Traditionally, when a base station broadcasts an RF signal,it broadcasts the signal in all directions. With beamforming, the basestation determines where a given target device (e.g., UE 102) is located(relative to the base station) and projects a stronger downlink RFsignal in that specific direction, thereby providing a faster (in termsof data rate) and stronger RF signal for the receiving device(s). Tochange the directionality of the RF signal when transmitting, a basestation can control the phase and relative amplitude of the RF signal ateach transmitter. For example, a base station may use an array ofantennas (referred to as a “phased array” or an “antenna array”) thatcreates a beam of RF waves that can be “steered” to point in differentdirections, without actually moving the antennas. Specifically, the RFcurrent from the transmitter is fed to the individual antennas with thecorrect phase relationship so that the radio waves from the separateantennas add together to increase the radiation in a desired direction,while cancelling to suppress radiation in undesired directions.

The term “cell” refers to a logical communication entity used forcommunication with a base station (e.g., over a carrier), and may beassociated with an identifier for distinguishing neighboring cells(e.g., a physical cell identifier (PCID), a virtual cell identifier(VCID)) operating via the same or a different carrier. In some examples,a carrier may support multiple cells, and different cells may beconfigured according to different protocol types (e.g., machine-typecommunication (MTC), narrowband Internet-of-Things (NB-IoT), enhancedmobile broadband (eMBB), or others) that may provide access fordifferent types of devices. In some cases, the term “cell” may refer toa portion of a geographic coverage area (e.g., a sector) over which thelogical entity operates.

FIG. 8 illustrates an exemplary system in which the RTT estimationprocedures disclosed herein are extended to massive MIMO and mmW systemsaccording to an aspect of the disclosure. In the example of FIG. 8,gNodeBs 202-206 are massive MIMO gNodeBs. To perform the RTT estimationprocedure described herein in massively beam-formed systems (e.g., MIMO,mmW), each physical gNodeB (e.g., gNodeBs 202-206) acts like a set ofmultiple “logical gNodeBs,” transmitting its RTT Measurement or RTTResponse signals on multiple beams (e.g., beams 1-4) on differenttime-frequency resources, in a TDM or FDM fashion. The RTTMeasurement/Response signals may (implicitly or explicitly) carryinformation about the identity of the gNodeB transmitting the signal, aswell as the beam-index (e.g., 1-4) used to transmit them. The UE (e.g.,UE 102) processes the RTT (Measurement/Response) signals received on thedownlink, as if they were transmitted by different gNodeBs. Inparticular, it records or reports the beam index (or indices) on whichthe RTT signals were received, in addition to the timestamps (e.g.,arrival times) described earlier.

During reception, the gNodeBs 202-206 record/report the beam index onwhich the RTT signals were received from the UE 102, and include thatinformation in the RTT Response payload, along with the timestamps(e.g., arrival time) described earlier. In case the gNodeBs 202-206 havefewer RF chains than the number of receiver-beams it uses, the UE 102may be commanded to repeat the RTT Measurement/Response messagesmultiple times, so that the gNodeB may sequentially cycle through theset of all receiver-beams that may be used to receive the RTT signalsfrom the UE 102, based on its limited base-band processing capabilities.An RF chain may be a receiver chain or a transmitter chain, and is thehardware utilized to receive or transmit RF signals of a given frequencyor set of frequencies. A device (e.g., a base station 202-206 or UE 102)may have multiple receiver/transmitter chains, and may thereby be ableto transmit and/or receive RF signals on multiple frequencies at thesame time.

In an aspect, in (massive) MIMO systems, either or both of the gNodeBs202-206 and the UE 102 may repeat their RTT Measurement/Report signalsmultiple times. The different repetitions may use either the same ordifferent transmission-beams. When a signal is repeated with the sametransmission-beam, it is intended to support reception-beam-sweeping (inaddition to coherent-combining if needed) at the receiving end-point(the UE 102 or a gNodeB 202-206).

In an aspect, the angle-of-arrival/departure (at the gNodeB 202-206)associated with the beam-index information may be used in conjunctionwith RTT estimates to compute the geographic position of the UE (RTTplus AoA/AoD based positioning).

FIG. 9 illustrates a reference point representation of a communicationsystem 900 based on a 5G NR network, in which RTT estimates may beproduced. Communication system 900 may be part of communication system100 for FIG. 2 (e.g. LMF 170 in FIG. 9 may correspond to LMF 225 in FIG.2). The communication system 900, for example, illustrates the UE 102connected to a plurality of gNodeBs 202 and 204, which are coupledtogether. By way of example, in FIG. 9, gNodeB 202 may be the servinggNodeB for UE 102. The gNodeBs 202 and 204 are coupled to a locationserver 170, which in a 5G core network (SGCN) is sometimes referred toas a Location Management Function (LMF) (e.g. LMF 225), and a corenetwork access node, which in a SGCN is sometimes referred to as anAccess and Mobility Management Function (AMF) 215. The gNodeBs 202 and204 may be coupled together and to the AMF 215 and LMF 170, e.g.,through a core network, or through integrated access and backhaul (IAB).It should be understood that there may be more UEs and/or more gNodeBsin the communication system 900.

As illustrated in FIG. 5A, in order to calculate an RTT, the UE 102 maytransmit an uplink RTT reference signal to the gNodeBs 202 and 204 and,after a processing delay Δ, each gNodeB 202 and 204 may transmit adownlink RTT reference signal to UE 102. The processing delay Δ, may becaused by various factors, such as internal processing time, as well asdelays caused by each gNodeB's own downlink sub-frame timing, e.g., thedownlink reference signal is aligned to the gNodeB's symbol boundaries.The UE 102 may determine for each gNodeB a total RTT between the time oftransmission (TOT) of the uplink RTT reference signal and the time ofarrival (TOA) of the downlink reference signal from each gNodeB. Thetotal RTT includes the processing delay Δ of the gNodeBs, which mayvary. Accordingly, to determine the net RTT, e.g., the time-of-flightround trip time for the signals, the processing delay Δ for each of thegNodeBs 202 and 204 is subtracted from the total RTT. The gNodeBs 202and 204 may provide their processing delays Δ to the UE 102 and the UE102 may determine the net RTT using the total RTT measured by the UE 102for each gNodeB. Alternatively, the gNodeBs 202 and 204 may providetheir processing delays Δ to the LMF 170, and the UE may provide thetotal RTT (or equivalently, the TOT of the uplink RTT reference signaland the TOA of the downlink reference signals) to the LMF 170, and theLMF 170 may determine the net RTT. Advantageously, the amount ofprocessing delays Δ may be provided, as opposed to providing the TOA andTOT, themselves, which reduces data length requirements.

Similarly, as illustrated in FIG. 5B, in order to calculate an RTT, thegNodeBs 202 and 204 may transmit downlink RTT reference signals to UE102, after a processing delay Δ in the UE 102, the UE 102 may transmituplink RTT reference signals to the gNodeBs 202 and 204. In thisarrangement, the total RTT from each gNodeB is the time between the TOTof the downlink uplink RTT reference signal and the TOA of the uplinkreference signal. To determine the net RTT, e.g., the actual round triptime for the signals, the processing delays Δ for the UE 102 to respondto each of the gNodeBs 202 and 204, is subtracted from the total RTT.The gNodeBs 202 and 204 may provide their total RTTs (or equivalently,the TOT of the downlink RTT reference signal and the TOA of the uplinkreference signals) to the UE 102 and the UE 102 may determine the netRTT using the measured processing delay Δ to return each uplink RTTreference signal. Alternatively, the gNodeBs 202 and 204 may providetheir total RTTs (or equivalently, the TOT of the downlink RTT referencesignal and the TOA of the uplink reference signals) to the LMF 170, andthe UE may provide the measured processing delay Δ to return each uplinkRTT reference signal to the LMF 170, and the LMF 170 may determine thenet RTT.

Thus, whether the gNodeBs 202 and 204 are each providing theirrespective processing delays Δ, or their respective total RTTs,sometimes collectively referred to herein as measured signaling data,one source of problems is that for the UE 102 to receive the signalingdata directly from each gNodeB 202 and 204, the UE 102 is required toreceive and decode these measurement signals transmitted by each of thegNodeBs, which would severely limit the measurement sensitivity. Forexample, while the serving gNodeB 202 may be within a connection rangewith the UE 102 in which the UE 102 may easily decode measurementsignals, other gNodeBs, such as gNodeB 204, may be in a connection rangein which the UE 102 cannot easily decode measurement signals, and thus,there is a high bit rate error. In comparison, the downlink RTTreference signals from each of the gNodeBs 202 and 204 are long in timeand/or wide in frequency. Signals with such large correlation gainscould overcome additional attenuation and accordingly have highsensitivity.

To overcome the measurement sensitivity, the gNodeBs may send theirmeasured signaling data to a single entity, e.g., either a servinggNodeB or the LMF 170. The gNodeBs may send their measured signalingdata to the single entity using the core network or integrated accessand backhaul (IAB) to avoid sensitivity problems. The single entity mayaggregate the signaling data for the UE 102, and send the aggregatedsignaling data to the UE 102 across. Thus, each gNodeB provides itssignaling data to an entity across a data path with low bit error rate.Moreover, the UE 102 may receive the aggregated signaling data from asingle entity, e.g., the serving gNodeB or the LMF, across a data pathwith low bit error rate.

FIG. 10 illustrates a call flow of a Mobile Originated Location Request(MO-LR) for RTT measurements for a UE 102, where the location server 170is used to aggregate the measured signal data from the gNodeBs 202 and204 and send an aggregated report of the measured signal data to the UE102. FIG. 10 illustrates, by way of example, the UE 102 initiating theRTT reference signal transmissions, where the UE 102 measures the totalRTT and the gNodeBs 202 and 204 measure and send their respectiveprocessing delays Δ to the location server 170. It should be understood,however, that if desired, the gNodeBs may initiate the RTT referencesignal transmissions, where the gNodeBs 202 and 204 measure and send thetotal RTTs to the location server 170 and the UE 102 measures itsprocessing delay Δ.

As illustrated, at stage A, the UE 102 transmits a Request RTT messageto the location server 170.

Stages B, C, and D are optional steps for on-demand downlink referencesignal transmissions. For example, as illustrated at optional stage B,the location server 170 may send to gNodeBs 202 and 204 a Request forgNB RTT configuration message.

At optional stage C, the gNodeBs 202 and 204 may send a gNB RTTconfiguration ready response message to the location server 170.

At optional stage D, the location server 170 may send to gNodeBs 202 and204 a Clear to send gNB RTT DL (downlink) RS (reference signal) message.

At stage E, the location server 170 may send to gNodeBs 202 and 204 agNB RTT assistance data (AD) with participating UEs message. Forexample, there may be more than one UE for which RTT measurements are tobe determined. The assistance data identifies the UEs with which thegNodeBs 202 and 204 are to engage.

At stage F, the gNodeBs 202 and 204 send gNB RTT AD ready responsemessage to the location server 170.

At stage G, the location server 170 sends to the UE 102 a UE RTTassistance data with list of participating gNBs message. For example,the assistance data identifies gNodeBs 202 and 204, as well as any othergNodeBs with which the UE 102 should engage for an RTT measurement. Itshould be understood, if there are multiple UEs, the location server 170may send appropriate assistance data to each UE participating in the RTTdetermination, if there are multiple UEs.

At optional stage H, the location server 170 sends a UE RTT clear tosend UL (uplink) RS message to the UE 102. Optional stage H, forexample, may be performed when on-demand UL reference signaltransmission.

At stage I, the UE 102 transmits an uplink RTT reference signal that isreceived by the gNodeBs 202 and 204.

At stage J, the gNodeBs 202 and 204 each transmit a downlink RTTreference signal, in response to the uplink RTT reference signalreceived in stage I, and after a processing delay Δ, e.g., between theTOA of the uplink RTT reference signal and the TOT of the downlink RTTreference signal, which is measured by the gNodeBs 202 and 204.

At stage K, gNodeB 202 sends to the location server 170 a gNB RTT reportof the detected DL TOT vs. UL TOA differences, i.e., the processingdelay Δ, measured by gNodeB 202 for all UEs for which RTT is beingmeasured, including UE 102.

At stage L, gNodeB 204 sends to the location server 170 a gNB RTT reportof the detected DL TOT vs. UL TOA differences, i.e., the processingdelay Δ, measured by gNodeB 204 for all UEs for which RTT is beingmeasured, including UE 102.

At stage M, the location server 170 aggregates the gNB RTT reports forthe processing delays Δ measured by each gNodeB 202 and 204 for all UEs,including UE 102.

At stage N, the location server 170 sends to the UE 102 the aggregatedreport of the processing delays Δ measured by each gNodeB 202 and 204for the UE 102.

At stage O, the UE 102 may determine the net RTT for each gNodeB 202 and204, e.g., using the total RTT measured by UE 102 for each gNodeB 202and 204, and the processing delays Δ measured by each gNodeB 202 and 204received in the aggregated report received at stage N. The UE 102 maydetermine the location of the UE 102 using the net RTT for at least thegNodeBs 202 and 204 and known positions of the gNodeBs 202 and 204,e.g., received in the assistance data from stage G. It is understoodthat while FIG. 10 illustrates only two gNodeBs for sake of simplicity,for location determination using trilateration RTT measurements fromthree or more gNodeBs may be used.

As discussed above, if desired, the gNodeBs may initiate the RTTreference signal transmissions (e.g., stage J may occur before stage I),where the gNodeBs 202 and 204 measure and send the total RTTs to thelocation server 170 at stages K and L, and the UE 102 measures itsprocessing delay Δ, which is used to determine the net RTT in stage O.

FIG. 11 illustrates a call flow of a Mobile Originated Location Request(MO-LR) for RTT measurements for a UE 102, where the serving gNodeB 202is used to aggregate the measured signal data from the gNodeBs 202 and204 and send an aggregated report of the measured signal data to the UE102. FIG. 11 illustrates, by way of example, the UE 102 initiating theRTT reference signal transmissions, where the UE 102 measures the totalRTT and the gNodeBs 202 and 204 measure their respective processingdelays Δ and gNodeB 204 sends its processing delay Δ to serving gNodeB202. It should be understood, however, that if desired, the gNodeBs mayinitiate the RTT reference signal transmissions, where the gNodeBs 202and 204 measure their respective total RTTs and gNodeB 204 sends itstotal RTT to serving gNodeB 202, and the UE 102 measures its processingdelay Δ.

As illustrated, at stage A, the UE 102 transmits a Request RTT messageto the gNodeB 202.

Stages B, C, and D are optional steps for on-demand downlink referencesignal transmissions. For example, as illustrated at optional stage B,the gNodeB 202 may send to gNodeB 204 a Request for DL configurationmessage.

At optional stage C, the gNodeB 204 may send a DL configuration readyresponse message to the gNodeB 202.

At optional stage D, the gNodeB 202 may send to gNodeB 204 a Clear tosend DL RS message.

At stage E, the gNodeB 202 may send to gNodeB 204 an assistance data(AD) with participating UEs message. For example, there may be more thanone UE for which RTT measurements are to be determined. The assistancedata identifies the UEs with which the gNodeBs 202 and 204 are toengage.

At stage F, the gNodeB 202 sends a gNB AD ready response message to thegNodeB 202.

At stage G, the gNodeB 202 sends to the UE 102 an assistance data withlist of participating gNBs message. For example, the assistance dataidentifies gNodeBs 202 and 204, as well as any other gNodeBs with whichthe UE 102 should engage for an RTT measurement. It should beunderstood, if there are multiple UEs, the gNodeB 202 may sendappropriate assistance data to each UE participating in the RTTdetermination, if there are multiple UEs.

At optional stage H, the gNodeB 202 sends a Clear to send UL RS messageto the UE 102. Optional stage H, for example, may be performed whenon-demand UL reference signal transmission.

At stage I, the UE 102 transmits an uplink RTT reference signal that isreceived by the gNodeBs 202 and 204.

At stage J, the gNodeBs 202 and 204 each transmit a downlink RTTreference signal, in response to the uplink RTT reference signalreceived in stage I, and after a processing delay Δ, e.g., between theTOA of the uplink RTT reference signal and the TOT of the downlink RTTreference signal, which is measured by the gNodeBs 202 and 204.

At stage K, gNodeB 204 sends to the gNodeB 202 a gNB RTT report of thedetected DL TOT vs. UL TOA differences, i.e., the processing delay Δ,measured by gNodeB 204 for all UEs for which RTT is being measured,including UE 102.

At stage L, the gNodeB 202 aggregates the gNB RTT reports for theprocessing delays Δ measured by each gNodeB 202 and 204 for all UEs,including UE 102.

At stage M, the gNodeB 202 sends to the UE 102 the aggregated report ofthe processing delays Δ measured by each gNodeB 202 and 204 for the UE102.

At stage N, the UE 102 may determine the net RTT for each gNodeB 202 and204, e.g., using the total RTT measured by UE 102 for each gNodeB 202and 204, and the processing delays Δ measured by each gNodeB 202 and 204received in the aggregated report received at stage N. The UE 102 maydetermine the location of the UE 102 using the net RTT for at least thegNodeBs 202 and 204 and known positions of the gNodeBs 202 and 204,e.g., received in the assistance data from stage G. It is understoodthat while FIG. 11 illustrates only two gNodeBs for sake of simplicity,for location determination using trilateration RTT measurements fromthree or more gNodeBs may be used.

As discussed above, if desired, the gNodeBs may initiate the RTTreference signal transmissions (e.g., stage J may occur before stage I),where the gNodeBs 202 and 204 measure and send the total RTTs to thelocation server 170 at stages K and L, and the UE 102 measures itsprocessing delay Δ, which is used to determine the net RTT in stage N.

FIG. 12 illustrates a call flow of a Network Initiated Location Request(NI-LR) for RTT measurements for a UE 102, where the location server 170is used to request the RTT determination and to aggregate the measuredsignal data from the gNodeBs 202 and 204. FIG. 12 illustrates, by way ofexample, the gNodeBs initiating the RTT reference signal transmissions,where the gNodeBs 202 and 204 measure and send the total RTTs to thelocation server 170 and the UE 102 measures and sends its processingdelay Δ to the location server 170. It should be understood, however,that if desired, the UE 102 may initiate the RTT reference signaltransmissions, where the UE 102 measures and sends the total RTT to thelocation server 170 and the gNodeBs 202 and 204 measure and send theirrespective processing delays Δ to the location server 170.

As illustrated, at stage A, the location server 170 sends a Request UERTT configuration message to the UE 102.

At stage B, the UE 102 sends a UE RTT configuration ready responsemessage to the location server 170.

Stages C, D, and E are optional steps for on-demand downlink referencesignal transmissions. For example, as illustrated at optional stage C,the location server 170 may send to gNodeBs 202 and 204 a Request forgNB RTT configuration message.

At optional stage D, the gNodeBs 202 and 204 may send a gNB RTTconfiguration ready response message to the location server 170.

At optional stage E, the location server 170 may send to gNodeBs 202 and204 a Clear to send gNB RTT DL RS message.

At stage F, the location server 170 may send to gNodeBs 202 and 204 agNB RTT assistance data (AD) with participating UEs message. Forexample, there may be more than one UE for which RTT measurements are tobe determined. The assistance data identifies the UEs with which thegNodeBs 202 and 204 are to engage.

At stage G, the gNodeBs 202 and 204 send gNB RTT AD ready responsemessage to the location server 170.

At stage H, the location server 170 sends to the UE 102 a UE RTTassistance data with list of participating gNBs message. For example,the assistance data identifies gNodeBs 202 and 204, as well as any othergNodeBs with which the UE 102 should engage for an RTT measurement. Itshould be understood, if there are multiple UEs, the location server 170may send appropriate assistance data to each UE participating in the RTTdetermination, if there are multiple UEs.

At optional stage I, the location server 170 sends a UE RTT clear tosend UL (uplink) RS message to the UE 102. Optional stage I, forexample, may be performed when on-demand UL reference signaltransmission.

At stage J, the gNodeBs 202 and 204 each transmit a downlink RTTreference signal to the UE 102.

At stage K, the UE 102 transmit uplink RTT reference signals to thegNodeBs 202 and 204, in response to the downlink RTT reference signalsreceived in stage J, and after a processing delay Δ, e.g., between theTOA of the downlink RTT reference signal and the TOT of the uplink RTTreference signal, which is measured by the UE 102.

At stage L, the UE 102 sends a RTT report of the detected UL TOT vs. DLTOA differences, i.e., the processing delays Δ, for each gNodeB 202 and204 for the UE.

At stage M, gNodeB 202 sends to the location server 170 a gNB RTT reportof the detected UL TOT vs DL TOA differences, i.e., the total RTT,measured by gNodeB 202 for all UEs for which RTT is being measured,including UE 102.

At stage N, gNodeB 204 sends to the location server 170 a gNB RTT reportof the detected UL TOT vs DL TOA differences, i.e., the total RTT,measured by gNodeB 204 for all UEs for which RTT is being measured,including UE 102.

At stage O, the location server 170 aggregates the gNB RTT reports forthe total RTTs measured by each gNodeB 202 and 204 and the processingdelays Δ for all UEs, including UE 102.

At stage P, the location server 170 may determine the net RTT for eachgNodeB 202 and 204, e.g., using the processing delays Δ measured by UE102 for each gNodeB 202 and 204, and the total RTT measured by eachgNodeB 202 and 204 from the aggregated report of stage O. The locationserver 170 may determine the location of the UE 102 using the net RTTfor at least the gNodeBs 202 and 204 and known positions of the gNodeBs202 and 204. It is understood that while FIG. 12 illustrates only twogNodeBs for sake of simplicity, for location determination usingtrilateration RTT measurements from three or more gNodeBs may be used.

As discussed above, if desired, the UE 102 may initiate the RTTreference signal transmissions (e.g., stage K may occur before stage J),where the gNodeBs 202 and 204 measure and send their processing delays Δto the location server 170 at stages M and N, and the UE 102 measuresthe total RTTs, which is used to determine the net RTTs in stage P.

FIG. 13 illustrates a call flow of a Network Initiated Location Request(NI-LR) for RTT measurements for a UE 102, where the serving gNodeB 202is used to request the RTT determination and the location server 170 isused to aggregate the measured signal data from the gNodeBs 202 and 204.Advantageously, by using the serving gNodeB 202, as illustrated in FIG.13, the end-to-end response time may be less than the implementationillustrated in FIG. 12 because there are fewer hops among the networkentities. FIG. 13 illustrates, by way of example, the gNodeBs initiatingthe RTT reference signal transmissions, where the gNodeBs 202 and 204measure and send the total RTTs to the location server 170 and the UE102 measures and sends its processing delay Δ to the location server170. It should be understood, however, that if desired, the UE 102 mayinitiate the RTT reference signal transmissions, where the UE 102measures and sends the total RTT to the location server 170 and thegNodeBs 202 and 204 measure and send their respective processing delaysΔ to the location server 170.

As illustrated, at stage A, the gNodeB 202 sends a Request UE RTTconfiguration message to the UE 102.

At stage B, the UE 102 sends a UE RTT configuration ready responsemessage to the gNodeB 202.

Stages C, D, and E are optional steps for on-demand downlink referencesignal transmissions. For example, as illustrated at optional stage C,the gNodeB 202 may send to gNodeB 204 a Request DL configurationmessage.

At optional stage D, the gNodeB 204 may send a DL configuration readyresponse message to the gNodeB 202.

At optional stage E, the gNodeB 202 may send to gNodeB 204 a Clear tosend DL RS message.

At stage F, the gNodeB 202 may send to gNodeB 204 a assistance data (AD)with participating UEs message. For example, there may be more than oneUE for which RTT measurements are to be determined. The assistance dataidentifies the UEs with which the gNodeBs 202 and 204 are to engage.

At stage G, the gNodeB 204 send gNB RTT AD ready response message to thegNodeB 202.

At stage H, the gNodeB 202 sends to the UE 102 a UE RTT assistance datawith list of participating gNBs message. For example, the assistancedata identifies gNodeBs 202 and 204, as well as any other gNodeBs withwhich the UE 102 should engage for an RTT measurement. It should beunderstood, if there are multiple UEs, the gNodeB 202 may sendappropriate assistance data to each UE participating in the RTTdetermination, if there are multiple UEs.

At optional stage I, the gNodeB 202 sends a UE RTT clear to send UL(uplink) RS message to the UE 102. Optional stage I, for example, may beperformed when on-demand UL reference signal transmission.

At stage J, the gNodeBs 202 and 204 each transmit a downlink RTTreference signal to the UE 102.

At stage K, the UE 102 transmit uplink RTT reference signals to thegNodeBs 202 and 204, in response to the downlink RTT reference signalsreceived in stage J, and after a processing delay Δ, e.g., between theTOA of the downlink RTT reference signal and the TOT of the uplink RTTreference signal, which is measured by the UE 102.

At stage L, the UE 102 sends a RTT report of the detected UL TOT vs. DLTOA differences, i.e., the processing delays Δ, for each gNodeB 202 and204 for the UE.

At stage M, gNodeB 202 sends to the location server 170 a gNB RTT reportof the detected UL TOT vs DL TOA differences, i.e., the total RTT,measured by gNodeB 202 for all UEs for which RTT is being measured,including UE 102.

At stage N, gNodeB 204 sends to the location server 170 a gNB RTT reportof the detected UL TOT vs DL TOA differences, i.e., the total RTT,measured by gNodeB 204 for all UEs for which RTT is being measured,including UE 102.

At stage O, the location server 170 aggregates the gNB RTT reports forthe total RTTs measured by each gNodeB 202 and 204 and the processingdelays Δ for all UEs, including UE 102.

At stage P, the location server 170 may determine the net RTT for eachgNodeB 202 and 204, e.g., using the processing delays Δ measured by UE102 for each gNodeB 202 and 204, and the total RTT measured by eachgNodeB 202 and 204 from the aggregated report of stage O. The locationserver 170 may determine the location of the UE 102 using the net RTTfor at least the gNodeBs 202 and 204 and known positions of the gNodeBs202 and 204. It is understood that while FIG. 12 illustrates only twogNodeBs for sake of simplicity, for location determination usingtrilateration RTT measurements from three or more gNodeBs may be used.

As discussed above, if desired, the UE 102 may initiate the RTTreference signal transmissions (e.g., stage K may occur before stage J),where the gNodeBs 202 and 204 measure and send their processing delays Δto the location server 170 at stages M and N, and the UE 102 measuresthe total RTTs, which is used to determine the net RTTs in stage P.

FIG. 14 illustrates an exemplary method 1400 for determining around-trip time (RTT) for signals between a user equipment (UE) (e.g.,UE 102) and a plurality of network nodes (gNodeBs) (e.g., gNodeBs202-204) in a wireless network performed by the UE 102. In an aspect,the first gNodeB is a serving gNodeB for the UE 102. The method 1400 maybe performed by, for example, the communication system 900 illustratedin FIG. 9 employing one or more of the call flows described in FIGS.10-11.

At 1402, the UE 102 transmits, to at least a first gNodeB and a secondgNodeB, an uplink RTT reference signal, e.g., as illustrated at stage Iin FIGS. 10 and 11.

At 1404, the UE 102 receives, from each of the first gNodeB and thesecond gNodeB, downlink RTT reference signals, wherein each of the firstgNodeB and the second gNodeB measure signaling data related to theuplink RTT reference signal and the downlink RTT reference signaltransmitted by the first gNodeB and the second gNodeB, wherein thesignaling data comprises one of a processing delay between a time ofarrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal. By way of example, step 1404 is illustratedat stage J in FIGS. 10 and 11.

At 1406, the UE 102 receives, from a single entity in the wirelessnetwork, an aggregated report of the measured signaling data for thefirst gNodeB and the second gNodeB, as illustrated at stage N in FIG. 10and stage M in FIG. 11.

At 1408, the UE calculates a net RTT between the UE and each of thefirst gNodeB and the second gNodeB based on the measured signaling datafor the first gNodeB and the second gNodeB received in the aggregatedreport and corresponding signaling data measured by the UE, wherein thecorresponding signaling data comprises one of a total RTT between theTOT of the uplink RTT reference signal and the TOA of the downlink RTTreference signal or a processing delay between the TOA of the downlinkRTT reference signal and a TOT of the downlink RTT reference signal, andthe net RTT is determined using the total RTT and the processing delay.Step 1408, for example, is illustrated at stage O in FIG. 10 and stage Pin FIG. 11.

In one aspect, the UE 102 may further determine a location of the UEusing at least the net RTT between the UE and each of the first gNodeBand the second gNodeB and a known position of the each of the firstgNodeB and the second gNodeB, as illustrated at stage O in FIG. 10 andstage P in FIG. 11.

In one aspect, the uplink RTT reference signal is transmitted beforereceiving the downlink RTT reference signals from each of the firstgNodeB and the second gNodeB, and wherein the signaling data measured bythe first gNodeB and the second gNodeB comprises the processing delay inthe first gNodeB and the second gNodeB, and the corresponding signalingdata measured by the UE comprises the total RTT.

In one aspect, separate uplink RTT reference signals are transmitted tothe first gNodeB and the second gNodeB after receiving the downlink RTTreference signals, and wherein the signaling data measured by the firstgNodeB and the second gNodeB comprises the total RTT, and thecorresponding signaling data measured by the UE comprises the processingdelay in the UE.

In one aspect, the single entity in the wireless network is the firstgNodeB, e.g., as illustrated at stage M in FIG. 11. For example, thefirst gNodeB may be a serving gNodeB for the UE.

In one aspect, the single entity in the wireless network is a locationserver, e.g., as illustrated at stage N in FIG. 10.

In one aspect, the second gNodeB is a neighbor gNodeB of the firstgNodeB within a communication range.

FIG. 15 illustrates an exemplary method 1500 for determining around-trip time (RTT) for signals between a user equipment (UE) (e.g.,UE 102) and a plurality of network nodes (gNodeBs) (e.g., gNodeBs202-204) in a wireless network performed by a first gNodeB (e.g., gNodeB202 or 204) in the plurality of gNodeBs. In an aspect, the first gNodeBis a serving gNodeB for the UE 102. In another aspect, the first gNodeBmay be a neighboring gNodeB. The method 1500 may be performed by, forexample, the communication system 900 illustrated in FIG. 9 employingone or more of the call flows described in FIGS. 10-13.

At 1502, the first gNodeB receives, from the UE, an uplink RTT referencesignal, as illustrated, e.g., at stage I in FIGS. 10 and 11 and stage Kat FIGS. 12 and 13.

At 1504, the first gNodeB transits, to the UE, a downlink RTT referencesignal as illustrated, e.g., at stage J in FIGS. 10 and 11 and stage Jat FIGS. 12 and 13.

At 1506, the first gNodeB measures signaling data related to the uplinkRTT reference signal and the downlink RTT reference signal, wherein thesignaling data comprises one of a processing delay between a time ofarrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal, as illustrated at stage J in FIGS. 10 and11 and stage J at FIGS. 12 and 13.

At 1508, the first gNodeB sends, to an entity in the wireless networkother than the UE, a report of the signaling data, as illustrated atstage K or L in FIG. 10, stage K in FIG. 11, stages M or N in FIGS. 12and 13.

In an aspect, the uplink RTT reference signal is received before thedownlink RTT reference signal is transmitted, and wherein the signalingdata measured by the first gNodeB comprises the processing delay in thefirst gNodeB.

In an aspect, the uplink RTT reference signal is received after thedownlink RTT reference signal is transmitted, and wherein the signalingdata measured by the first gNodeB comprises the total RTT.

In an aspect, the entity in the wireless network other than the UE is asecond gNodeB, as illustrated at stage K in FIG. 11.

In an aspect, the entity in the wireless network other than the UE is alocation server, as illustrated at stages K and L in FIG. 10 and stagesM and N in FIGS. 12 and 13. For example, the first gNodeB is a servinggNodeB for the UE, as illustrated at stage K in FIG. 10 and stage M inFIGS. 12 and 13.

In an aspect, the report of the signaling data is sent to the entity inthe wireless network other than the UE using a core network orintegrated access and backhaul (IAB).

In an aspect, the first gNodeB may further receive, from a second UE, asecond uplink RTT reference signal, transmit, to the second UE, a seconddownlink RTT reference signal, and measure a second signaling datarelated to the second uplink RTT reference signal and the seconddownlink RTT reference signal, wherein the second signaling datacomprises one of a second processing delay between a TOA of the seconduplink RTT reference signal and a TOT of the second downlink RTTreference signal or a second total RTT between the TOT of the seconddownlink RTT reference signal and the TOA of the second uplink RTTreference signal. For example, the first gNodeB may receive, from asecond gNodeB, a report of a third signaling data measured by the secondgNodeB related to the second uplink RTT reference signal and thirddownlink RTT reference signal transmitted by the second gNodeB, whereinthe third signaling data comprises one of a third processing delaybetween a TOA of the second uplink RTT reference signal and a TOT of thethird downlink RTT reference signal or a third total RTT between the TOTof the third downlink RTT reference signal and the TOA of the seconduplink RTT reference signal, as illustrated at stage K in FIG. 11. Thefirst gNodeB may aggregate the second signaling data and the thirdsignaling data, as illustrated at stage L of FIG. 11. The first gNodeBmay transmit, to the second UE, an aggregated report of the secondsignaling data and the third signaling data, as illustrated at stage Min FIG. 11. For example, the second signaling data may be sent to theentity in the wireless network other than the UE in the report of thesignaling data, as illustrated at stages K in FIGS. 10 and 11, and stageM in FIGS. 12 and 13.

In an aspect, the entity in the wireless network other than the UEreceives, from at least one other gNodeB, a report of signaling datameasured by the other gNodeB related to the uplink RTT reference signalreceived by the other gNodeB from the UE and a second downlink RTTreference signal transmitted by the other gNodeB to the UE, wherein thesignaling data comprises one of a processing delay between a TOA of theuplink RTT reference signal received by the other gNodeB and a TOT ofthe second downlink RTT reference signal or a total RTT between the TOTof the second downlink RTT reference signal and the TOA of the uplinkRTT reference signal received by the other gNodeB, as illustrated atstage N in FIGS. 12 and 13.

FIG. 16 illustrates an exemplary method 1600 for determining around-trip time (RTT) for signals between a user equipment (UE) (e.g.,UE 102) and a plurality of network nodes (gNodeBs) (e.g., gNodeBs202-204) in a wireless network performed by a first gNodeB (e.g., gNodeB202 or 204) in the plurality of gNodeBs. In an aspect, the first gNodeBis a serving gNodeB for the UE 102. The method 1600 may be performed by,for example, the communication system 900 illustrated in FIG. 9employing one or more of the call flows described in FIGS. 10-13.

At 1602, the first gNodeB receives, from the UE, an uplink RTT referencesignal, as illustrated, e.g., at stage I in FIGS. 10 and 11 and stage Kat FIGS. 12 and 13.

At 1604, the first gNodeB transits, to the UE, a downlink RTT referencesignal as illustrated, e.g., at stage J in FIGS. 10 and 11 and stage Jat FIGS. 12 and 13.

At 1606, the first gNodeB measures first signaling data related to theuplink RTT reference signal and the downlink RTT reference signal,wherein the first signaling data comprises one of a processing delaybetween a time of arrival (TOA) of the uplink RTT reference signal and atime of transmission (TOT) of the downlink RTT reference signal or atotal RTT between the TOT of the downlink RTT reference signal and theTOA of the uplink RTT reference signal, as illustrated at stage J inFIGS. 10 and 11 and stage J at FIGS. 12 and 13.

At 1608, the first gNodeB receives, from a second gNodeB, a report of asecond signaling data measured by the second gNodeB related to theuplink RTT reference signal received by the second gNodeB and a seconddownlink RTT reference signal transmitted by the second gNodeB, whereinthe second signaling data comprises one of a second processing delaybetween a TOA of the uplink RTT reference signal at the second gNodeBand a TOT of the second downlink RTT reference signal or a second totalRTT between the TOT of the second downlink RTT reference signal and theTOA of the second uplink RTT reference signal, as illustrated at stage Kin FIG. 11.

At 1610, the first gNodeB aggregates the signaling data and the secondsignaling data, as illustrated at stage L in FIG. 11.

At 1612, the first gNodeB transmits, to the UE, an aggregated report ofthe signaling data and the second signaling data, as illustrated atstage M in FIG. 11.

In one aspect, the uplink RTT reference signal is received before thedownlink RTT reference signal is transmitted, and wherein the signalingdata measured by the first gNodeB comprises the processing delay in thefirst gNodeB and the second signaling data measured by the second gNodeBcomprises the processing delay in the second gNodeB.

In one aspect, the uplink RTT reference signal is received after thedownlink RTT reference signal is transmitted, and wherein the signalingdata measured by the first gNodeB comprises the total RTT measured bythe first gNodeB and the second signaling data measured by the secondgNodeB comprises the total RTT measured by the second gNodeB.

In one aspect, the first gNodeB is a serving gNodeB for the UE.Additionally, the second gNodeB may be neighbor gNodeB of the firstgNodeB within communication range of the UE.

FIG. 16 illustrates an exemplary method 1700 for determining a locationfor a first user equipment (UE) (e.g., UE 102) using round-trip time(RTT) for signals between the first UE and a plurality of network nodes(gNodeBs) (e.g., gNodeBs 202-204) in a wireless network performed by alocation server (e.g., LMF 170). In an aspect, the first gNodeB is aserving gNodeB for the UE 102. The method 1600 may be performed by, forexample, the communication system 900 illustrated in FIG. 9 employingone or more of the call flows described in FIGS. 10, 12-13.

At 1702, the location server receives, from a first gNodeB, a report offirst signaling data related to a time of arrival (TOA) of uplink RTTreference signals received by the first gNodeB from a plurality of UEsincluding the first UE and time of transmission (TOT) of downlink RTTreference signals transmitted by the first gNodeB to each of theplurality of UEs, wherein for each UE in the plurality of UEs, the firstsignaling data comprises one of a processing delay between the TOA ofthe uplink RTT reference signal and the TOT of the downlink RTTreference signal or a total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal, asillustrated at stage K in FIG. 10 and stage M in FIGS. 12 and 13.

At 1704, the location server receives, from a second gNodeB, a report ofsecond signaling data related to the TOA of uplink RTT reference signalsreceived by the second gNodeB from the plurality of UEs including thefirst UE and TOT of downlink RTT reference signals transmitted by thesecond gNodeB to each of the plurality of UEs, wherein for each UE inthe plurality of UEs, the second signaling data comprises one of theprocessing delay between the TOA of the uplink RTT reference signal andthe TOT of the downlink RTT reference signal or the total RTT betweenthe TOT of the downlink RTT reference signal and the TOA of the uplinkRTT reference signal, as illustrated at stage L in FIG. 10 and stage Nin FIGS. 12 and 13.

At 1706, the location server aggregates, for the first UE in theplurality of UEs, the first signaling data and the second signalingdata, as illustrated at stage M in FIG. 10 and stage O in FIGS. 12 and13.

At 1708, the location of the UE is determined using at least a net RTTbetween the first UE and each of the first gNodeB and the second gNodeB,wherein the net RTT is determined using the first signaling data and thesecond signaling data aggregated for the first UE, as illustrated atstage O in FIG. 10 and stage P in FIGS. 12 and 13.

In one aspect, the first signaling data measured by the first gNodeBcomprises the processing delay in the first gNodeB, and the secondsignaling data measured by the second gNodeB comprises the processingdelay in the second gNodeB.

In one aspect, the first signaling data measured by the first gNodeBcomprises the total RTT measured by the first gNodeB, and the secondsignaling data measured by the second gNodeB comprises the total RTTmeasured by the second gNodeB.

In one aspect, the location server sends, to the first UE, theaggregation of the first signaling data and the second signaling data,as illustrated at stage N in FIG. 10. The first UE determines the netRTT using the first signaling data and the second signaling data andcorresponding signaling data measured by the first UE comprising one ofa total RTT between the TOT of the uplink RTT reference signal and theTOA of the downlink RTT reference signal or a processing delay betweenthe TOA of the downlink RTT reference signal and a TOT of the downlinkRTT reference signal, and the net RTT is determined using the total RTTand the processing delay; and wherein the first UE determines thelocation for the first UE using at least the net RTT between the UE andeach of the first gNodeB and the second gNodeB and a known position ofthe each of the first gNodeB and the second gNodeB, as illustrated atstage O in FIG. 10. For example, the location determination session maybe initiated by the first UE, as illustrated at stage A in FIG. 10.

In one aspect, the location server receives corresponding signaling datameasured by the first UE comprising one of a total RTT between the TOTof the uplink RTT reference signal and the TOA of the downlink RTTreference signal or a processing delay between the TOA of the downlinkRTT reference signal and a TOT of the downlink RTT reference signal, asillustrated at stage L in FIGS. 12 and 13. The location serverdetermines the net RTT using the aggregation of the first signaling dataand the second signaling data for the first UE and the correspondingsignaling data measured by the first UE, wherein the net RTT isdetermined using the total RTT and the processing delay, as illustratedat stage P of FIGS. 12 and 13. The location server determines thelocation for the first UE using at least the net RTT between the UE andeach of the first gNodeB and the second gNodeB and a known position ofthe each of the first gNodeB and the second gNodeB as illustrated atstage P of FIGS. 12 and 13. For example, the location determinationsession may be initiated by the location server, as illustrated at stageA in FIG. 12.

In one aspect, the location server may send RTT assistance data to thefirst gNodeB and the second gNodeB, as illustrated at stage E in FIG. 10and stage F in FIG. 12. The location server may send RTT assistance datato the UE, as illustrated at stage G in FIG. 10 and stage H in FIG. 12.

In one aspect, RTT assistance data may be sent from the first gNodeB tothe second gNodeB, as illustrated by stage F in FIG. 13. Additionally,RTT assistance data may be sent from the first gNodeB to the first UE,as illustrated by stage H in FIG. 13.

In one aspect, the first gNodeB is a serving gNodeB for the first UE.

FIG. 18 illustrates an example user equipment apparatus 1800 representedas a series of interrelated functional modules connected by a commonbus. A module for transmitting an uplink RTT reference signal 1802 maycorrespond at least in some aspects to, for example, a communicationdevice, such as communication device 308 in FIG. 3, and/or a processingsystem, such as processing system 332 in FIG. 3, as discussed herein. Amodule for downlink RTT reference signals 1804 may correspond at leastin some aspects to, for example, a communication device, such ascommunication device 308 in FIG. 3, and/or a processing system, such asprocessing system 332 in FIG. 3, as discussed herein. A module forreceiving an aggregated report of the measured signaling data 1806 maycorrespond at least in some aspects to, for example, a communicationdevice, such as communication device 308 in FIG. 3, and/or a processingsystem, such as processing system 332 in FIG. 3, as discussed herein. Amodule for calculating a net RTT 1808 may correspond at least in someaspects to, for example, a communication device, such as communicationdevice 308 in FIG. 3, and/or a processing system, such as processingsystem 332 in FIG. 3, as discussed herein.

Thus, a user equipment apparatus may include a means for transmitting,to at least a first gNodeB and a second gNodeB, an uplink RTT referencesignal, which may be, e.g., the transmitter 310 and one or moreprocessors in processing system 332 with dedicated hardware orimplementing executable code or software instructions in memorycomponent 338 such as the module for transmitting an uplink RTTreference signal 1802. A means for receiving, from each of the firstgNodeB and the second gNodeB, downlink RTT reference signals, whereineach of the first gNodeB and the second gNodeB measure signaling datarelated to the uplink RTT reference signal and the downlink RTTreference signal transmitted by the first gNodeB and the second gNodeB,wherein the signaling data comprises one of a processing delay between atime of arrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal may be, e.g., the receiver 312 and one ormore processors in processing system 332 with dedicated hardware orimplementing executable code or software instructions in memorycomponent 338 such as the module for downlink RTT reference signals1804. A means for receiving, from a single entity in the wirelessnetwork, an aggregated report of the measured signaling data for thefirst gNodeB and the second gNodeB may be, e.g., the receiver 312 andone or more processors in processing system 332 with dedicated hardwareor implementing executable code or software instructions in memorycomponent 338 such as the module for receiving an aggregated report ofthe measured signaling data 1806. A means for calculating a net RTTbetween the UE and each of the first gNodeB and the second gNodeB basedon the measured signaling data for the first gNodeB and the secondgNodeB received in the aggregated report and corresponding signalingdata measured by the UE, wherein the corresponding signaling datacomprises one of a total RTT between the TOT of the uplink RTT referencesignal and the TOA of the downlink RTT reference signal or a processingdelay between the TOA of the downlink RTT reference signal and a TOT ofthe downlink RTT reference signal, and the net RTT is determined usingthe total RTT and the processing delay may be, e.g., one or moreprocessors in the processing system 332 with dedicated hardware orimplementing executable code or software instructions in memorycomponent 338 such as the module for calculating a net RTT 1808.

Additionally, the user equipment apparatus may include a means fordetermining a location of the UE using at least the net RTT between theUE and each of the first gNodeB and the second gNodeB and a knownposition of the each of the first gNodeB and the second gNodeB, whichmay be, e.g., one or more processors in the processing system 332 withdedicated hardware or implementing executable code or softwareinstructions in memory component 338.

FIG. 19 illustrates an example network node apparatus 1900 (e.g., agNodeB) represented as a series of interrelated functional modulesconnected by a common bus. A module for receiving an uplink RTTreference signal 1902 may correspond at least in some aspects to, forexample, a communication device, such as communication device 314 inFIG. 3, and/or a processing system, such as processing system 334 inFIG. 3, as discussed herein. A module for transmitting a downlink RTTreference signal 1904 may correspond at least in some aspects to, forexample, a communication device, such as communication device 314 inFIG. 3, and/or a processing system, such as processing system 334 inFIG. 3, as discussed herein. A module for measuring signaling data 1906may correspond at least in some aspects to, for example, a processingsystem, such as processing system 334 in FIG. 3, as discussed herein. Amodule for sending a report of the signaling data 1908 may correspond atleast in some aspects to, for example, a communication device, such ascommunication device 314 in FIG. 3, and/or a processing system, such asprocessing system 334 in FIG. 3, as discussed herein.

Thus, a network node apparatus may include a means for receiving, fromthe UE, an uplink RTT reference signal, which may be, e.g., the receiver318 and one or more processors in processing system 334 with dedicatedhardware or implementing executable code or software instructions inmemory component 340 such as the module for receiving an uplink RTTreference signal 1902. A means for transmitting, to the UE, a downlinkRTT reference signal may be, e.g., the transmitter 316 and one or moreprocessors in processing system 334 with dedicated hardware orimplementing executable code or software instructions in memorycomponent 340 such as the module for transmitting a downlink RTTreference signal 1904. A means for measuring signaling data related tothe uplink RTT reference signal and the downlink RTT reference signal,wherein the signaling data comprises one of a processing delay between atime of arrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal may be, e.g., one or more processors inprocessing system 334 with dedicated hardware or implementing executablecode or software instructions in memory component 340 such as the modulefor measuring signaling data 1906. A means for sending, to an entity inthe wireless network other than the UE, a report of the signaling datamay be, e.g., the transmitter 322 and one or more processors inprocessing system 334 with dedicated hardware or implementing executablecode or software instructions in memory component 340 such as the modulefor sending a report of the signaling data 1908.

In addition, the network node apparatus may include a means forreceiving, from a second UE, a second uplink RTT reference signal, whichmay be, e.g., the receiver 318 and one or more processors in processingsystem 334 with dedicated hardware or implementing executable code orsoftware instructions in memory component 340 such as the module forreceiving an uplink RTT reference signal 1902. A means for transmitting,to the second UE, a second downlink RTT reference signal may be, e.g.,the transmitter 316 and one or more processors in processing system 334with dedicated hardware or implementing executable code or softwareinstructions in memory component 340 such as the module for transmittinga downlink RTT reference signal 1904. A means for measuring a secondsignaling data related to the second uplink RTT reference signal and thesecond downlink RTT reference signal, wherein the second signaling datacomprises one of a second processing delay between a TOA of the seconduplink RTT reference signal and a TOT of the second downlink RTTreference signal or a second total RTT between the TOT of the seconddownlink RTT reference signal and the TOA of the second uplink RTTreference signal may be, e.g., one or more processors in processingsystem 334 with dedicated hardware or implementing executable code orsoftware instructions in memory component 340 such as the module formeasuring signaling data 1906. In addition, the network node apparatusmay include a means for receiving, from a second gNodeB, a report of athird signaling data measured by the second gNodeB related to the seconduplink RTT reference signal and third downlink RTT reference signaltransmitted by the second gNodeB, wherein the third signaling datacomprises one of a third processing delay between a TOA of the seconduplink RTT reference signal and a TOT of the third downlink RTTreference signal or a third total RTT between the TOT of the thirddownlink RTT reference signal and the TOA of the second uplink RTTreference signal, which may be, e.g., the receiver 318 and one or moreprocessors in processing system 334 with dedicated hardware orimplementing executable code or software instructions in memorycomponent 340 such as the module for receiving an uplink RTT referencesignal 1902. A means for aggregating the second signaling data and thethird signaling data may be, e.g., one or more processors in processingsystem 334 with dedicated hardware or implementing executable code orsoftware instructions in memory component 340. A means for transmitting,to the second UE, an aggregated report of the second signaling data andthe third signaling data may be, e.g., the transmitter 316 and one ormore processors in processing system 334 with dedicated hardware orimplementing executable code or software instructions in memorycomponent 340.

FIG. 20 illustrates another example network node apparatus 2000 (e.g., agNodeB) represented as a series of interrelated functional modulesconnected by a common bus. A module for receiving an uplink RTTreference signal 2002 may correspond at least in some aspects to, forexample, a communication device, such as communication device 314 inFIG. 3, and/or a processing system, such as processing system 334 inFIG. 3, as discussed herein. A module for transmitting a downlink RTTreference signal 2004 may correspond at least in some aspects to, forexample, a communication device, such as communication device 314 inFIG. 3, and/or a processing system, such as processing system 334 inFIG. 3, as discussed herein. A module for measuring signaling data 2006may correspond at least in some aspects to, for example, a processingsystem, such as processing system 334 in FIG. 3, as discussed herein. Amodule for receiving a report of a signaling data measured by the secondgNodeB 2008 may correspond at least in some aspects to, for example, acommunication device, such as communication device 314 in FIG. 3, and/ora processing system, such as processing system 334 in FIG. 3, asdiscussed herein. A module for aggregating the signaling data 2010 maycorrespond at least in some aspects to, for example, a processingsystem, such as processing system 334 in FIG. 3, as discussed herein. Amodule for transmitting an aggregated report of the signaling data 2012may correspond at least in some aspects to, for example, a communicationdevice, such as communication device 314 in FIG. 3, and/or a processingsystem, such as processing system 334 in FIG. 3, as discussed herein.

Thus, a network node apparatus (first gNodeB)may include a means forreceiving, from the UE, an uplink RTT reference signal, which may be,e.g., the receiver 318 and one or more processors in processing system334 with dedicated hardware or implementing executable code or softwareinstructions in memory component 340 such as the module for receiving anuplink RTT reference signal 2002. A means for transmitting, to the UE, adownlink RTT reference signal may be, e.g., the transmitter 316 and oneor more processors in processing system 334 with dedicated hardware orimplementing executable code or software instructions in memorycomponent 340 such as the module for transmitting a downlink RTTreference signal 2004. A means for measuring, by the first gNodeB, firstsignaling data related to the uplink RTT reference signal and thedownlink RTT reference signal, wherein the first signaling datacomprises one of a processing delay between a time of arrival (TOA) ofthe uplink RTT reference signal and a time of transmission (TOT) of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal may be, e.g., one or more processors in processing system 334with dedicated hardware or implementing executable code or softwareinstructions in memory component 340 such as the module for measuringsignaling data 2006. A means for receiving, from a second gNodeB, areport of a second signaling data measured by the second gNodeB relatedto the uplink RTT reference signal received by the second gNodeB and asecond downlink RTT reference signal transmitted by the second gNodeB,wherein the second signaling data comprises one of a second processingdelay between a TOA of the uplink RTT reference signal at the secondgNodeB and a TOT of the second downlink RTT reference signal or a secondtotal RTT between the TOT of the second downlink RTT reference signaland the TOA of the second uplink RTT reference signal may be, e.g., thereceiver 318 and one or more processors in processing system 334 withdedicated hardware or implementing executable code or softwareinstructions in memory component 340 such as the module for receiving areport of a signaling data measured by the second gNodeB 2008. A meansfor aggregating the signaling data and the second signaling data may be,e.g., one or more processors in processing system 334 with dedicatedhardware or implementing executable code or software instructions inmemory component 340 such as the module for aggregating the signalingdata 2010. A means for transmitting, to the UE, an aggregated report ofthe signaling data and the second signaling data may be, e.g., thetransmitter 316 and one or more processors in processing system 334 withdedicated hardware or implementing executable code or softwareinstructions in memory component 340 such as the module for transmittingan aggregated report of the signaling data 2012.

FIG. 21 illustrates another example network node apparatus 2100 (e.g., alocation server) represented as a series of interrelated functionalmodules connected by a common bus. A module for receiving a report offirst signaling data 2102 may correspond at least in some aspects to,for example, a communication device, such as communication device 326 inFIG. 3, and/or a processing system, such as processing system 336 inFIG. 3, as discussed herein. A module for receiving a report of secondsignaling data 2104 may correspond at least in some aspects to, forexample, a communication device, such as communication device 326 inFIG. 3, and/or a processing system, such as processing system 336 inFIG. 3, as discussed herein. A module for aggregating the firstsignaling data and the second signaling data 2106 may correspond atleast in some aspects to, for example, a processing system, such asprocessing system 336 in FIG. 3, as discussed herein. In someimplementations, the network node apparatus 2100 may include a modulefor calculating the net RTT 2108, which may correspond at least in someaspects to, for example, a processing system, such as processing system336 in FIG. 3, as discussed herein. In some implementations, the networknode apparatus 2100 may also include a module for determining thelocation of the first UE 2110, which may correspond at least in someaspects to, for example, a processing system, such as processing system336 in FIG. 3, as discussed herein.

Thus, a location server may include a means for receiving, from a firstgNodeB, a report of first signaling data related to a time of arrival(TOA) of uplink RTT reference signals received by the first gNodeB froma plurality of UEs including the first UE and time of transmission (TOT)of downlink RTT reference signals transmitted by the first gNodeB toeach of the plurality of UEs, wherein for each UE in the plurality ofUEs, the first signaling data comprises one of a processing delaybetween the TOA of the uplink RTT reference signal and the TOT of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal, which may be, e.g., the receiver 330 and one or more processorsin processing system 336 with dedicated hardware or implementingexecutable code or software instructions in memory component 342 such asthe module for receiving a report of first signaling data 2102. A meansfor receiving, from a second gNodeB, a report of second signaling datarelated to the TOA of uplink RTT reference signals received by thesecond gNodeB from the plurality of UEs including the first UE and TOTof downlink RTT reference signals transmitted by the second gNodeB toeach of the plurality of UEs, wherein for each UE in the plurality ofUEs, the second signaling data comprises one of the processing delaybetween the TOA of the uplink RTT reference signal and the TOT of thedownlink RTT reference signal or the total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal may be, e.g., the receiver 330 and one or more processors inprocessing system 336 with dedicated hardware or implementing executablecode or software instructions in memory component 342 such as the modulefor receiving a report of second signaling data 2104. A means foraggregating, for the first UE in the plurality of UEs, the firstsignaling data and the second signaling data may be, e.g., one or moreprocessors in processing system 336 with dedicated hardware orimplementing executable code or software instructions in memorycomponent 342 such as the module for aggregating the first signalingdata and the second signaling data 2106. The location of the UE may bedetermined using at least a net RTT between the first UE and each of thefirst gNodeB and the second gNodeB, wherein the net RTT is determinedusing the first signaling data and the second signaling data aggregatedfor the first UE.

In addition, the location server may include means for receivingcorresponding signaling data measured by the first UE comprising one ofa total RTT between the TOT of the uplink RTT reference signal and theTOA of the downlink RTT reference signal or a processing delay betweenthe TOA of the downlink RTT reference signal and a TOT of the downlinkRTT reference signal, which may be, e.g., the receiver 330 and one ormore processors in processing system 336 with dedicated hardware orimplementing executable code or software instructions in memorycomponent 342. A means for determining the net RTT using the aggregationof the first signaling data and the second signaling data for the firstUE and the corresponding signaling data measured by the first UE,wherein the net RTT is determined using the total RTT and the processingdelay may be, e.g., one or more processors in processing system 336 withdedicated hardware or implementing executable code or softwareinstructions in memory component 342 such as the module for module forcalculating the net RTT 2108. A means for determining the location forthe first UE using at least the net RTT between the UE and each of thefirst gNodeB and the second gNodeB and a known position of the each ofthe first gNodeB and the second gNodeB may be, e.g., one or moreprocessors in processing system 336 with dedicated hardware orimplementing executable code or software instructions in memorycomponent 342 such as the module for determining the location of thefirst UE using at least the net RTT and known positions of the gNodeBs2110.

The functionality of the modules of FIGS. 18-21 may be implemented invarious ways consistent with the teachings herein. In some designs, thefunctionality of these modules may be implemented as one or moreelectrical components. In some designs, the functionality of theseblocks may be implemented as a processing system including one or moreprocessor components. In some designs, the functionality of thesemodules may be implemented using, for example, at least a portion of oneor more integrated circuits (e.g., an ASIC). As discussed herein, anintegrated circuit may include a processor, software, other relatedcomponents, or some combination thereof. Thus, the functionality ofdifferent modules may be implemented, for example, as different subsetsof an integrated circuit, as different subsets of a set of softwaremodules, or a combination thereof. Also, it will be appreciated that agiven subset (e.g., of an integrated circuit and/or of a set of softwaremodules) may provide at least a portion of the functionality for morethan one module.

In addition, the components and functions represented by FIGS. 18-21, aswell as other components and functions described herein, may beimplemented using any suitable means. Such means also may beimplemented, at least in part, using corresponding structure as taughtherein. For example, the components described above in conjunction withthe “module for” components of FIGS. 18-21 also may correspond tosimilarly designated “means for” functionality. Thus, in some aspectsone or more of such means may be implemented using one or more ofprocessor components, integrated circuits, or other suitable structureas taught herein.

Those of skill in the art will appreciate that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Further, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the aspects disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The methods, sequences and/or algorithms described in connection withthe aspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in random access memory (RAM), flashmemory, read-only memory (ROM), erasable programmable ROM (EPROM),electrically erasable programmable ROM (EEPROM), registers, hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. An exemplary storage medium is coupled to the processor suchthat the processor can read information from, and write information to,the storage medium. In the alternative, the storage medium may beintegral to the processor. The processor and the storage medium mayreside in an ASIC. The ASIC may reside in a user terminal (e.g., UE). Inthe alternative, the processor and the storage medium may reside asdiscrete components in a user terminal.

In one or more exemplary aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

One implementation (1) may be a method for determining a round-trip time(RTT) for signals between a user equipment (UE) and a plurality ofnetwork nodes (gNodeBs) in a wireless network performed by a firstgNodeB in the plurality of gNodeBs, the method comprising: receiving,from the UE, an uplink RTT reference signal; transmitting, to the UE, adownlink RTT reference signal; measuring signaling data related to theuplink RTT reference signal and the downlink RTT reference signal,wherein the signaling data comprises one of a processing delay between atime of arrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal; and sending, to an entity in the wirelessnetwork other than the UE, a report of the signaling data.

There may be some implementations (2) of the above described method (1),wherein the uplink RTT reference signal is received before the downlinkRTT reference signal is transmitted, and wherein the signaling datameasured by the first gNodeB comprises the processing delay in the firstgNodeB.

There may be some implementations (3) of the above described method (1),wherein the uplink RTT reference signal is received after the downlinkRTT reference signal is transmitted, and wherein the signaling datameasured by the first gNodeB comprises the total RTT.

There may be some implementations (4) of the above described method(1)), wherein the entity in the wireless network other than the UE is asecond gNodeB.

There may be some implementations (5) of the above described method(1)), wherein the entity in the wireless network other than the UE is alocation server.

There may be some implementations (6) of the above described method (5),wherein the first gNodeB is a serving gNodeB for the UE.

There may be some implementations (7) of the above described method (1),wherein the report of the signaling data is sent to the entity in thewireless network other than the UE using a core network or integratedaccess and backhaul (IAB).

There may be some implementations (8) of the above described method (1),further comprising: receiving, from a second UE, a second uplink RTTreference signal; transmitting, to the second UE, a second downlink RTTreference signal; and measuring a second signaling data related to thesecond uplink RTT reference signal and the second downlink RTT referencesignal, wherein the second signaling data comprises one of a secondprocessing delay between a TOA of the second uplink RTT reference signaland a TOT of the second downlink RTT reference signal or a second totalRTT between the TOT of the second downlink RTT reference signal and theTOA of the second uplink RTT reference signal.

There may be some implementations (9) of the above described method (8),further comprising: receiving, from a second gNodeB, a report of a thirdsignaling data measured by the second gNodeB related to the seconduplink RTT reference signal and third downlink RTT reference signaltransmitted by the second gNodeB, wherein the third signaling datacomprises one of a third processing delay between a TOA of the seconduplink RTT reference signal and a TOT of the third downlink RTTreference signal or a third total RTT between the TOT of the thirddownlink RTT reference signal and the TOA of the second uplink RTTreference signal; aggregating the second signaling data and the thirdsignaling data; and transmitting, to the second UE, an aggregated reportof the second signaling data and the third signaling data.

There may be some implementations (10) of the above described method(8), wherein the second signaling data is sent to the entity in thewireless network other than the UE in the report of the signaling data.

There may be some implementations (11) of the above described method(1), wherein the entity in the wireless network other than the UEreceives, from at least one other gNodeB, a report of signaling datameasured by the other gNodeB related to the uplink RTT reference signalreceived by the other gNodeB from the UE and a second downlink RTTreference signal transmitted by the other gNodeB to the UE, wherein thesignaling data comprises one of a processing delay between a TOA of theuplink RTT reference signal received by the other gNodeB and a TOT ofthe second downlink RTT reference signal or a total RTT between the TOTof the second downlink RTT reference signal and the TOA of the uplinkRTT reference signal received by the other gNodeB.

One implementation (12) may be a network node (first gNodeB) in awireless network configured for determining a round-trip time (RTT) forsignals between a user equipment (UE) and a plurality of network nodes(gNodeBs), comprising: at least one transceiver configured to: receive,from the UE, an uplink RTT reference signal; transmit, to the UE, adownlink RTT reference signal; at least one memory; and at least oneprocessor coupled to the at least one transceiver and the at least onememory and configured to measuring signaling data related to the uplinkRTT reference signal and the downlink RTT reference signal, wherein thesignaling data comprises one of a processing delay between a time ofarrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal; and the at least one transceiver is furtherconfigured to: sending, to an entity in the wireless network other thanthe UE, a report of the signaling data.

There may be some implementations (There may be some implementations(13) of the above described network node (12), wherein the uplink RTTreference signal is received before the downlink RTT reference signal istransmitted, and wherein the signaling data measured by the first gNodeBcomprises the processing delay in the first gNodeB.

There may be some implementations (There may be some implementations(14) of the above described network node (12), wherein the uplink RTTreference signal is received after the downlink RTT reference signal istransmitted, and wherein the signaling data measured by the first gNodeBcomprises the total RTT.

There may be some implementations (There may be some implementations(15) of the above described network node (12), wherein the entity in thewireless network other than the UE is a second gNodeB.

There may be some implementations (16) of the above described networknode (12), wherein the entity in the wireless network other than the UEis a location server.

There may be some implementations (17) of the above described networknode (16), wherein the first gNodeB is a serving gNodeB for the UE.

There may be some implementations (18) of the above described networknode (12), wherein the report of the signaling data is sent to theentity in the wireless network other than the UE using a core network orintegrated access and backhaul (JAB).

There may be some implementations (19) of the above described networknode (12), wherein the at least one transceiver is further configuredto: receive, from a second UE, a second uplink RTT reference signal;transmit, to the second UE, a second downlink RTT reference signal; andthe at least one processor is further configured to measure a secondsignaling data related to the second uplink RTT reference signal and thesecond downlink RTT reference signal, wherein the second signaling datacomprises one of a second processing delay between a TOA of the seconduplink RTT reference signal and a TOT of the second downlink RTTreference signal or a second total RTT between the TOT of the seconddownlink RTT reference signal and the TOA of the second uplink RTTreference signal.

There may be some implementations (20) of the above described networknode (19), wherein the at least one transceiver is further configuredto: receive, from a second gNodeB, a report of a third signaling datameasured by the second gNodeB related to the second uplink RTT referencesignal and third downlink RTT reference signal transmitted by the secondgNodeB, wherein the third signaling data comprises one of a thirdprocessing delay between a TOA of the second uplink RTT reference signaland a TOT of the third downlink RTT reference signal or a third totalRTT between the TOT of the third downlink RTT reference signal and theTOA of the second uplink RTT reference signal; the at least oneprocessor is further configured to aggregate the second signaling dataand the third signaling data; and the at least one transceiver isfurther configured to transmit, to the second UE, an aggregated reportof the second signaling data and the third signaling data.

There may be some implementations (21) of the above described networknode (19), wherein the second signaling data is sent to the entity inthe wireless network other than the UE in the report of the signalingdata.

There may be some implementations (22) of the above described networknode (12), wherein the entity in the wireless network other than the UEreceives, from at least one other gNodeB, a report of signaling datameasured by the other gNodeB related to the uplink RTT reference signalreceived by the other gNodeB from the UE and a second downlink RTTreference signal transmitted by the other gNodeB to the UE, wherein thesignaling data comprises one of a processing delay between a TOA of theuplink RTT reference signal received by the other gNodeB and a TOT ofthe second downlink RTT reference signal or a total RTT between the TOTof the second downlink RTT reference signal and the TOA of the uplinkRTT reference signal received by the other gNodeB.

One implementation (23) may be a network node in a wireless networkconfigured for determining a round-trip time (RTT) for signals between auser equipment (UE) and a plurality of network nodes (gNodeBs),comprising: means for receiving, from the UE, an uplink RTT referencesignal; means for transmitting, to the UE, a downlink RTT referencesignal; means for measuring signaling data related to the uplink RTTreference signal and the downlink RTT reference signal, wherein thesignaling data comprises one of a processing delay between a time ofarrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal; and means for sending, to an entity in thewireless network other than the UE, a report of the signaling data.

There may be some implementations (24) of the above described networknode (23), wherein the uplink RTT reference signal is received beforethe downlink RTT reference signal is transmitted, and wherein thesignaling data measured by the first gNodeB comprises the processingdelay in the first gNodeB.

There may be some implementations (25) of the above described networknode (23), wherein the uplink RTT reference signal is received after thedownlink RTT reference signal is transmitted, and wherein the signalingdata measured by the first gNodeB comprises the total RTT.

There may be some implementations (26) of the above described networknode (23), wherein the entity in the wireless network other than the UEis a second gNodeB.

There may be some implementations (27) of the above described networknode (23), wherein the entity in the wireless network other than the UEis a location server.

There may be some implementations (28) of the above described networknode (27), wherein the first gNodeB is a serving gNodeB for the UE.

There may be some implementations (29) of the above described networknode (23), wherein the report of the signaling data is sent to theentity in the wireless network other than the UE using a core network orintegrated access and backhaul (JAB).

There may be some implementations (30) of the above described networknode (23), further comprising: means for receiving, from a second UE, asecond uplink RTT reference signal; means for transmitting, to thesecond UE, a second downlink RTT reference signal; and means formeasuring a second signaling data related to the second uplink RTTreference signal and the second downlink RTT reference signal, whereinthe second signaling data comprises one of a second processing delaybetween a TOA of the second uplink RTT reference signal and a TOT of thesecond downlink RTT reference signal or a second total RTT between theTOT of the second downlink RTT reference signal and the TOA of thesecond uplink RTT reference signal.

There may be some implementations (31) of the above described networknode (30), further comprising: means for receiving, from a secondgNodeB, a report of a third signaling data measured by the second gNodeBrelated to the second uplink RTT reference signal and third downlink RTTreference signal transmitted by the second gNodeB, wherein the thirdsignaling data comprises one of a third processing delay between a TOAof the second uplink RTT reference signal and a TOT of the thirddownlink RTT reference signal or a third total RTT between the TOT ofthe third downlink RTT reference signal and the TOA of the second uplinkRTT reference signal; means for aggregating the second signaling dataand the third signaling data; and means for transmitting, to the secondUE, an aggregated report of the second signaling data and the thirdsignaling data.

There may be some implementations (32) of the above described networknode (30), wherein the second signaling data is sent to the entity inthe wireless network other than the UE in the report of the signalingdata.

There may be some implementations (33) of the above described networknode (23), wherein the entity in the wireless network other than the UEreceives, from at least one other gNodeB, a report of signaling datameasured by the other gNodeB related to the uplink RTT reference signalreceived by the other gNodeB from the UE and a second downlink RTTreference signal transmitted by the other gNodeB to the UE, wherein thesignaling data comprises one of a processing delay between a TOA of theuplink RTT reference signal received by the other gNodeB and a TOT ofthe second downlink RTT reference signal or a total RTT between the TOTof the second downlink RTT reference signal and the TOA of the uplinkRTT reference signal received by the other gNodeB.

One implementation (34) may be a non-transitory storage medium includingprogram code stored thereon, the program code is operable to cause atleast one processor in a first network node (gNodeB) in a wirelessnetwork to operate for determining a round-trip time (RTT) for signalsbetween a user equipment (UE) and a plurality of network nodes (gNodeBs)in the wireless network, comprising: program code to receive, from theUE, an uplink RTT reference signal; program code to transmit, to the UE,a downlink RTT reference signal; program code to measure signaling datarelated to the uplink RTT reference signal and the downlink RTTreference signal, wherein the signaling data comprises one of aprocessing delay between a time of arrival (TOA) of the uplink RTTreference signal and a time of transmission (TOT) of the downlink RTTreference signal or a total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal; andprogram code to send, to an entity in the wireless network other thanthe UE, a report of the signaling data.

One implementation (35) may be a method for determining a round-triptime (RTT) for signals between a user equipment (UE) and a plurality ofnetwork nodes (gNodeBs) in a wireless network performed by a firstgNodeB in the plurality of gNodeBs, the method comprising: receiving,from the UE, an uplink RTT reference signal; transmitting, to the UE, adownlink RTT reference signal; measuring, by the first gNodeB, firstsignaling data related to the uplink RTT reference signal and thedownlink RTT reference signal, wherein the first signaling datacomprises one of a processing delay between a time of arrival (TOA) ofthe uplink RTT reference signal and a time of transmission (TOT) of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; receiving, from a second gNodeB, a report of a second signalingdata measured by the second gNodeB related to the uplink RTT referencesignal received by the second gNodeB and a second downlink RTT referencesignal transmitted by the second gNodeB, wherein the second signalingdata comprises one of a second processing delay between a TOA of theuplink RTT reference signal at the second gNodeB and a TOT of the seconddownlink RTT reference signal or a second total RTT between the TOT ofthe second downlink RTT reference signal and the TOA of the seconduplink RTT reference signal; aggregating the signaling data and thesecond signaling data; and transmitting, to the UE, an aggregated reportof the signaling data and the second signaling data.

There may be some implementations (36) of the above described method(35),), wherein the uplink RTT reference signal is received before thedownlink RTT reference signal is transmitted, and wherein the signalingdata measured by the first gNodeB comprises the processing delay in thefirst gNodeB and the second signaling data measured by the second gNodeBcomprises the processing delay in the second gNodeB.

There may be some implementations (37) of the above described method(35),), wherein the uplink RTT reference signal is received after thedownlink RTT reference signal is transmitted, and wherein the signalingdata measured by the first gNodeB comprises the total RTT measured bythe first gNodeB and the second signaling data measured by the secondgNodeB comprises the total RTT measured by the second gNodeB.

There may be some implementations (38) of the above described method(35), wherein the first gNodeB is a serving gNodeB for the UE.

There may be some implementations (39) of the above described method(35),), wherein the second gNodeB is a neighbor gNodeB of the firstgNodeB within communication range of the UE.

One implementation (40) may be a network node (first gNodeB) in awireless network configured for determining a round-trip time (RTT) forsignals between a user equipment (UE) and a plurality of network nodes(gNodeBs), comprising: at least one transceiver configured to: receive,from the UE, an uplink RTT reference signal; transmit, to the UE, adownlink RTT reference signal; receive, from a second gNodeB, a reportof a second signaling data measured by the second gNodeB related to theuplink RTT reference signal received by the second gNodeB and a seconddownlink RTT reference signal transmitted by the second gNodeB, whereinthe second signaling data comprises one of a second processing delaybetween a TOA of the uplink RTT reference signal at the second gNodeBand a TOT of the second downlink RTT reference signal or a second totalRTT between the TOT of the second downlink RTT reference signal and theTOA of the second uplink RTT reference signal; at least one memory; andat least one processor coupled to the at least one transceiver and theat least one memory and configured to: measure, by the first gNodeB,first signaling data related to the uplink RTT reference signal and thedownlink RTT reference signal, wherein the first signaling datacomprises one of a processing delay between a time of arrival (TOA) ofthe uplink RTT reference signal and a time of transmission (TOT) of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; aggregate the signaling data and the second signaling data; andwherein the at least one transceiver is further configured to transmit,to the UE, an aggregated report of the signaling data and the secondsignaling data.

There may be some implementations (41) of the above described networknode (40),), wherein the uplink RTT reference signal is received beforethe downlink RTT reference signal is transmitted, and wherein thesignaling data measured by the first gNodeB comprises the processingdelay in the first gNodeB and the second signaling data measured by thesecond gNodeB comprises the processing delay in the second gNodeB.

There may be some implementations (42) of the above described networknode (40), wherein the uplink RTT reference signal is received after thedownlink RTT reference signal is transmitted, and wherein the signalingdata measured by the first gNodeB comprises the total RTT measured bythe first gNodeB and the second signaling data measured by the secondgNodeB comprises the total RTT measured by the second gNodeB.

There may be some implementations (43) of the above described networknode (40), wherein the first gNodeB is a serving gNodeB for the UE.

There may be some implementations (44) of the above described networknode (40), wherein the second gNodeB is a neighbor gNodeB of the firstgNodeB within communication range of the UE.

One implementation (45) may be a network node (first gNodeB) in awireless network configured for determining a round-trip time (RTT) forsignals between a user equipment (UE) and a plurality of network nodes(gNodeBs), comprising: means for receiving, from the UE, an uplink RTTreference signal; means for transmitting, to the UE, a downlink RTTreference signal; means for measuring, by the first gNodeB, firstsignaling data related to the uplink RTT reference signal and thedownlink RTT reference signal, wherein the first signaling datacomprises one of a processing delay between a time of arrival (TOA) ofthe uplink RTT reference signal and a time of transmission (TOT) of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; means for receiving, from a second gNodeB, a report of a secondsignaling data measured by the second gNodeB related to the uplink RTTreference signal received by the second gNodeB and a second downlink RTTreference signal transmitted by the second gNodeB, wherein the secondsignaling data comprises one of a second processing delay between a TOAof the uplink RTT reference signal at the second gNodeB and a TOT of thesecond downlink RTT reference signal or a second total RTT between theTOT of the second downlink RTT reference signal and the TOA of thesecond uplink RTT reference signal; means for aggregating the signalingdata and the second signaling data; and means for transmitting, to theUE, an aggregated report of the signaling data and the second signalingdata.

There may be some implementations (46) of the above described networknode (45), wherein the uplink RTT reference signal is received beforethe downlink RTT reference signal is transmitted, and wherein thesignaling data measured by the first gNodeB comprises the processingdelay in the first gNodeB and the second signaling data measured by thesecond gNodeB comprises the processing delay in the second gNodeB.

There may be some implementations (47) of the above described networknode (45), wherein the uplink RTT reference signal is received after thedownlink RTT reference signal is transmitted, and wherein the signalingdata measured by the first gNodeB comprises the total RTT measured bythe first gNodeB and the second signaling data measured by the secondgNodeB comprises the total RTT measured by the second gNodeB.

There may be some implementations (48) of the above described networknode (45), wherein the first gNodeB is a serving gNodeB for the UE.

There may be some implementations (49) of the above described networknode (45), wherein the second gNodeB is a neighbor gNodeB of the firstgNodeB within communication range of the UE.

One implementation (50) may be a non-transitory storage medium includingprogram code stored thereon, the program code is operable to cause atleast one processor in a first network node (gNodeB) in a wirelessnetwork to operate for determining a round-trip time (RTT) for signalsbetween a user equipment (UE) and a plurality of network nodes (gNodeBs)in the wireless network, comprising: program code to receive, from theUE, an uplink RTT reference signal; program code to transmit, to the UE,a downlink RTT reference signal; program code to measure, by the firstgNodeB, first signaling data related to the uplink RTT reference signaland the downlink RTT reference signal, wherein the first signaling datacomprises one of a processing delay between a time of arrival (TOA) ofthe uplink RTT reference signal and a time of transmission (TOT) of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; program code to receive, from a second gNodeB, a report of asecond signaling data measured by the second gNodeB related to theuplink RTT reference signal received by the second gNodeB and a seconddownlink RTT reference signal transmitted by the second gNodeB, whereinthe second signaling data comprises one of a second processing delaybetween a TOA of the uplink RTT reference signal at the second gNodeBand a TOT of the second downlink RTT reference signal or a second totalRTT between the TOT of the second downlink RTT reference signal and theTOA of the second uplink RTT reference signal; program code to aggregatethe signaling data and the second signaling data; and program code totransmit, to the UE, an aggregated report of the signaling data and thesecond signaling data.

There may be some implementations (51) of the above describednon-transitory storage medium (50), wherein the uplink RTT referencesignal is received before the downlink RTT reference signal istransmitted, and wherein the signaling data measured by the first gNodeBcomprises the processing delay in the first gNodeB and the secondsignaling data measured by the second gNodeB comprises the processingdelay in the second gNodeB.

There may be some implementations (52) of the above describednon-transitory storage medium (50), wherein the uplink RTT referencesignal is received after the downlink RTT reference signal istransmitted, and wherein the signaling data measured by the first gNodeBcomprises the total RTT measured by the first gNodeB and the secondsignaling data measured by the second gNodeB comprises the total RTTmeasured by the second gNodeB.

There may be some implementations (53) of the above describednon-transitory storage medium (50), wherein the first gNodeB is aserving gNodeB for the UE.

There may be some implementations (54) of the above describednon-transitory storage medium (50), wherein the second gNodeB is aneighbor gNodeB of the first gNodeB within communication range of theUE.

One implementation (55) may be a method for determining a location for afirst user equipment (UE) using round-trip time (RTT) for signalsbetween the first UE and a plurality of network nodes (gNodeBs) in awireless network performed by a location server, the method comprising:receiving, from a first gNodeB, a report of first signaling data relatedto a time of arrival (TOA) of uplink RTT reference signals received bythe first gNodeB from a plurality of UEs including the first UE and timeof transmission (TOT) of downlink RTT reference signals transmitted bythe first gNodeB to each of the plurality of UEs, wherein for each UE inthe plurality of UEs, the first signaling data comprises one of aprocessing delay between the TOA of the uplink RTT reference signal andthe TOT of the downlink RTT reference signal or a total RTT between theTOT of the downlink RTT reference signal and the TOA of the uplink RTTreference signal; receiving, from a second gNodeB, a report of secondsignaling data related to the TOA of uplink RTT reference signalsreceived by the second gNodeB from the plurality of UEs including thefirst UE and TOT of downlink RTT reference signals transmitted by thesecond gNodeB to each of the plurality of UEs, wherein for each UE inthe plurality of UEs, the second signaling data comprises one of theprocessing delay between the TOA of the uplink RTT reference signal andthe TOT of the downlink RTT reference signal or the total RTT betweenthe TOT of the downlink RTT reference signal and the TOA of the uplinkRTT reference signal; and aggregating, for the first UE in the pluralityof UEs, the first signaling data and the second signaling data; andwherein the location of the UE is determined using at least a net RTTbetween the first UE and each of the first gNodeB and the second gNodeB,wherein the net RTT is determined using the first signaling data and thesecond signaling data aggregated for the first UE.

There may be some implementations (56) of the above described method(55), wherein the first signaling data measured by the first gNodeBcomprises the processing delay in the first gNodeB, and the secondsignaling data measured by the second gNodeB comprises the processingdelay in the second gNodeB.

There may be some implementations (57) of the above described method(55), wherein the first signaling data measured by the first gNodeBcomprises the total RTT measured by the first gNodeB, and the secondsignaling data measured by the second gNodeB comprises the total RTTmeasured by the second gNodeB.

There may be some implementations (58) of the above described method(55), wherein the location server sends, to the first UE, theaggregation of the first signaling data and the second signaling dataand the first UE determines the net RTT using the first signaling dataand the second signaling data and corresponding signaling data measuredby the first UE comprising one of a total RTT between the TOT of theuplink RTT reference signal and the TOA of the downlink RTT referencesignal or a processing delay between the TOA of the downlink RTTreference signal and a TOT of the downlink RTT reference signal, and thenet RTT is determined using the total RTT and the processing delay; andwherein the first UE determines the location for the first UE using atleast the net RTT between the UE and each of the first gNodeB and thesecond gNodeB and a known position of the each of the first gNodeB andthe second gNodeB.

There may be some implementations (59) of the above described method(58), wherein a location determination session is initiated by the firstUE.

There may be some implementations (60) of the above described method(55), further comprising: receiving corresponding signaling datameasured by the first UE comprising one of a total RTT between the TOTof the uplink RTT reference signal and the TOA of the downlink RTTreference signal or a processing delay between the TOA of the downlinkRTT reference signal and a TOT of the downlink RTT reference signal;determining the net RTT using the aggregation of the first signalingdata and the second signaling data for the first UE and thecorresponding signaling data measured by the first UE, wherein the netRTT is determined using the total RTT and the processing delay; anddetermining the location for the first UE using at least the net RTTbetween the UE and each of the first gNodeB and the second gNodeB and aknown position of the each of the first gNodeB and the second gNodeB.

There may be some implementations (61) of the above described method(60), wherein a location determination session is initiated by thelocation server.

There may be some implementations (62) of the above described method(60), further comprising: sending RTT assistance data to the firstgNodeB and the second gNodeB; and sending RTT assistance data to the UE.

There may be some implementations (63) of the above described method(60), wherein: RTT assistance data is sent from the first gNodeB to thesecond gNodeB; and RTT assistance data is sent from the first gNodeB tothe first UE.

There may be some implementations (64) of the above described method(63), wherein the first gNodeB is a serving gNodeB for the first UE.

One implementation (65) may be a network node (location server) in awireless network configured for determining a location for a first userequipment (UE) using round-trip time (RTT) for signals between the firstUE and a plurality of network nodes (gNodeBs), comprising: at least onenetwork interface configured to: receive, from a first gNodeB, a reportof first signaling data related to a time of arrival (TOA) of uplink RTTreference signals received by the first gNodeB from a plurality of UEsincluding the first UE and time of transmission (TOT) of downlink RTTreference signals transmitted by the first gNodeB to each of theplurality of UEs, wherein for each UE in the plurality of UEs, the firstsignaling data comprises one of a processing delay between the TOA ofthe uplink RTT reference signal and the TOT of the downlink RTTreference signal or a total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal;receive, from a second gNodeB, a report of second signaling data relatedto the TOA of uplink RTT reference signals received by the second gNodeBfrom the plurality of UEs including the first UE and TOT of downlink RTTreference signals transmitted by the second gNodeB to each of theplurality of UEs, wherein for each UE in the plurality of UEs, thesecond signaling data comprises one of the processing delay between theTOA of the uplink RTT reference signal and the TOT of the downlink RTTreference signal or the total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal; and atleast one memory; and at least one processor coupled to the at least onenetwork interface and the at least one memory and configured toaggregate, for the first UE in the plurality of UEs, the first signalingdata and the second signaling data; and wherein the location of the UEis determined using at least a net RTT between the first UE and each ofthe first gNodeB and the second gNodeB, wherein the net RTT isdetermined using the first signaling data and the second signaling dataaggregated for the first UE.

There may be some implementations (66) of the above described networknode (65), wherein the first signaling data measured by the first gNodeBcomprises the processing delay in the first gNodeB, and the secondsignaling data measured by the second gNodeB comprises the processingdelay in the second gNodeB.

There may be some implementations (67) of the above described networknode (65), wherein the first signaling data measured by the first gNodeBcomprises the total RTT measured by the first gNodeB, and the secondsignaling data measured by the second gNodeB comprises the total RTTmeasured by the second gNodeB.

There may be some implementations (68) of the above described networknode (65), wherein the location server sends, to the first UE, theaggregation of the first signaling data and the second signaling dataand the first UE determines the net RTT using the first signaling dataand the second signaling data and corresponding signaling data measuredby the first UE comprising one of a total RTT between the TOT of theuplink RTT reference signal and the TOA of the downlink RTT referencesignal or a processing delay between the TOA of the downlink RTTreference signal and a TOT of the downlink RTT reference signal, and thenet RTT is determined using the total RTT and the processing delay; andwherein the first UE determines the location for the first UE using atleast the net RTT between the UE and each of the first gNodeB and thesecond gNodeB and a known position of the each of the first gNodeB andthe second gNodeB.

There may be some implementations (69) of the above described networknode (68), wherein a location determination session is initiated by thefirst UE.

There may be some implementations (70) of the above described networknode (65), wherein the at least one network interface is furtherconfigured to: receive corresponding signaling data measured by thefirst UE comprising one of a total RTT between the TOT of the uplink RTTreference signal and the TOA of the downlink RTT reference signal or aprocessing delay between the TOA of the downlink RTT reference signaland a TOT of the downlink RTT reference signal; the at least oneprocessor is further configured to: determine the net RTT using theaggregation of the first signaling data and the second signaling datafor the first UE and the corresponding signaling data measured by thefirst UE, wherein the net RTT is determined using the total RTT and theprocessing delay; and determine the location for the first UE using atleast the net RTT between the UE and each of the first gNodeB and thesecond gNodeB and a known position of the each of the first gNodeB andthe second gNodeB.

There may be some implementations (71) of the above described networknode (70), wherein a location determination session is initiated by thelocation server.

There may be some implementations (72) of the above described networknode (70), wherein the at least one network interface is furtherconfigured to: send RTT assistance data to the first gNodeB and thesecond gNodeB; and send RTT assistance data to the UE.

There may be some implementations (73) of the above described networknode (70), wherein: RTT assistance data is sent from the first gNodeB tothe second gNodeB; and RTT assistance data is sent from the first gNodeBto the first UE.

There may be some implementations (74) of the above described networknode (73), wherein the first gNodeB is a serving gNodeB for the firstUE.

One implementation (75) may be a network node (location server) in awireless network configured for determining a location for a first userequipment (UE) using round-trip time (RTT) for signals between the firstUE and a plurality of network nodes (gNodeBs), comprising: means forreceiving, from a first gNodeB, a report of first signaling data relatedto a time of arrival (TOA) of uplink RTT reference signals received bythe first gNodeB from a plurality of UEs including the first UE and timeof transmission (TOT) of downlink RTT reference signals transmitted bythe first gNodeB to each of the plurality of UEs, wherein for each UE inthe plurality of UEs, the first signaling data comprises one of aprocessing delay between the TOA of the uplink RTT reference signal andthe TOT of the downlink RTT reference signal or a total RTT between theTOT of the downlink RTT reference signal and the TOA of the uplink RTTreference signal; means for receiving, from a second gNodeB, a report ofsecond signaling data related to the TOA of uplink RTT reference signalsreceived by the second gNodeB from the plurality of UEs including thefirst UE and TOT of downlink RTT reference signals transmitted by thesecond gNodeB to each of the plurality of UEs, wherein for each UE inthe plurality of UEs, the second signaling data comprises one of theprocessing delay between the TOA of the uplink RTT reference signal andthe TOT of the downlink RTT reference signal or the total RTT betweenthe TOT of the downlink RTT reference signal and the TOA of the uplinkRTT reference signal; and means for aggregating, for the first UE in theplurality of UEs, the first signaling data and the second signalingdata; and wherein the location of the UE is determined using at least anet RTT between the first UE and each of the first gNodeB and the secondgNodeB, wherein the net RTT is determined using the first signaling dataand the second signaling data aggregated for the first UE.

There may be some implementations (76) of the above described networknode (75), wherein the first signaling data measured by the first gNodeBcomprises the processing delay in the first gNodeB, and the secondsignaling data measured by the second gNodeB comprises the processingdelay in the second gNodeB.

There may be some implementations (77) of the above described networknode (75), wherein the first signaling data measured by the first gNodeBcomprises the total RTT measured by the first gNodeB, and the secondsignaling data measured by the second gNodeB comprises the total RTTmeasured by the second gNodeB.

There may be some implementations (78) of the above described networknode (75), wherein the location server sends, to the first UE, theaggregation of the first signaling data and the second signaling dataand the first UE determines the net RTT using the first signaling dataand the second signaling data and corresponding signaling data measuredby the first UE comprising one of a total RTT between the TOT of theuplink RTT reference signal and the TOA of the downlink RTT referencesignal or a processing delay between the TOA of the downlink RTTreference signal and a TOT of the downlink RTT reference signal, and thenet RTT is determined using the total RTT and the processing delay; andwherein the first UE determines the location for the first UE using atleast the net RTT between the UE and each of the first gNodeB and thesecond gNodeB and a known position of the each of the first gNodeB andthe second gNodeB.

There may be some implementations (79) of the above described networknode (78), wherein a location determination session is initiated by thefirst UE.

There may be some implementations (80) of the above described networknode (75), further comprising: means for receiving correspondingsignaling data measured by the first UE comprising one of a total RTTbetween the TOT of the uplink RTT reference signal and the TOA of thedownlink RTT reference signal or a processing delay between the TOA ofthe downlink RTT reference signal and a TOT of the downlink RTTreference signal; means for determining the net RTT using theaggregation of the first signaling data and the second signaling datafor the first UE and the corresponding signaling data measured by thefirst UE, wherein the net RTT is determined using the total RTT and theprocessing delay; and means for determining the location for the firstUE using at least the net RTT between the UE and each of the firstgNodeB and the second gNodeB and a known position of the each of thefirst gNodeB and the second gNodeB.

There may be some implementations (81) of the above described networknode (80), wherein a location determination session is initiated by thelocation server.

There may be some implementations (82) of the above described networknode (80), further comprising: sending RTT assistance data to the firstgNodeB and the second gNodeB; and sending RTT assistance data to the UE.

There may be some implementations (83) of the above described networknode (80), wherein: RTT assistance data is sent from the first gNodeB tothe second gNodeB; and RTT assistance data is sent from the first gNodeBto the first UE.

There may be some implementations (84) of the above described networknode (83), wherein the first gNodeB is a serving gNodeB for the firstUE.

One implementation (85) may be a non-transitory storage medium includingprogram code stored thereon, the program code is operable to cause atleast one processor in a location server to operate for determininglocation for a first user equipment (UE) using round-trip time (RTT) forsignals between the first UE and a plurality of network nodes (gNodeBs)in a wireless network comprising: program code to receive, from a firstgNodeB, a report of first signaling data related to a time of arrival(TOA) of uplink RTT reference signals received by the first gNodeB froma plurality of UEs including the first UE and time of transmission (TOT)of downlink RTT reference signals transmitted by the first gNodeB toeach of the plurality of UEs, wherein for each UE in the plurality ofUEs, the first signaling data comprises one of a processing delaybetween the TOA of the uplink RTT reference signal and the TOT of thedownlink RTT reference signal or a total RTT between the TOT of thedownlink RTT reference signal and the TOA of the uplink RTT referencesignal; program code to receive, from a second gNodeB, a report ofsecond signaling data related to the TOA of uplink RTT reference signalsreceived by the second gNodeB from the plurality of UEs including thefirst UE and TOT of downlink RTT reference signals transmitted by thesecond gNodeB to each of the plurality of UEs, wherein for each UE inthe plurality of UEs, the second signaling data comprises one of theprocessing delay between the TOA of the uplink RTT reference signal andthe TOT of the downlink RTT reference signal or the total RTT betweenthe TOT of the downlink RTT reference signal and the TOA of the uplinkRTT reference signal; and program code to aggregate, for the first UE inthe plurality of UEs, the first signaling data and the second signalingdata; and wherein the location of the UE is determined using at least anet RTT between the first UE and each of the first gNodeB and the secondgNodeB, wherein the net RTT is determined using the first signaling dataand the second signaling data aggregated for the first UE.

While the foregoing disclosure shows illustrative aspects of thedisclosure, it should be noted that various changes and modificationscould be made herein without departing from the scope of the disclosureas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the aspects of the disclosuredescribed herein need not be performed in any particular order.Furthermore, although elements of the disclosure may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

What is claimed is:
 1. A method for determining a round-trip time (RTT)for signals between a user equipment (UE) and a plurality of networknodes (gNodeBs) in a wireless network performed by the UE, the methodcomprising: transmitting, to at least a first gNodeB and a secondgNodeB, an uplink RTT reference signal; receiving, from each of thefirst gNodeB and the second gNodeB, downlink RTT reference signals,wherein each of the first gNodeB and the second gNodeB measure signalingdata related to the uplink RTT reference signal and the downlink RTTreference signal transmitted by the first gNodeB and the second gNodeB,wherein the signaling data comprises one of a processing delay between atime of arrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal; receiving, from a single entity in thewireless network, an aggregated report of the measured signaling datafor the first gNodeB and the second gNodeB; and calculating a net RTTbetween the UE and each of the first gNodeB and the second gNodeB basedon the measured signaling data for the first gNodeB and the secondgNodeB received in the aggregated report and corresponding signalingdata measured by the UE, wherein the corresponding signaling datacomprises one of a total RTT between the TOT of the uplink RTT referencesignal and the TOA of the downlink RTT reference signal or a processingdelay between the TOA of the downlink RTT reference signal and a TOT ofthe downlink RTT reference signal, and the net RTT is determined usingthe total RTT and the processing delay.
 2. The method of claim 1,further comprising determining a location of the UE using at least thenet RTT between the UE and each of the first gNodeB and the secondgNodeB and a known position of the each of the first gNodeB and thesecond gNodeB.
 3. The method of claim 1, wherein the uplink RTTreference signal is transmitted before receiving the downlink RTTreference signals from each of the first gNodeB and the second gNodeB,and wherein the signaling data measured by the first gNodeB and thesecond gNodeB comprises the processing delay in the first gNodeB and thesecond gNodeB, and the corresponding signaling data measured by the UEcomprises the total RTT.
 4. The method of claim 1, wherein separateuplink RTT reference signals are transmitted to the first gNodeB and thesecond gNodeB after receiving the downlink RTT reference signals, andwherein the signaling data measured by the first gNodeB and the secondgNodeB comprises the total RTT, and the corresponding signaling datameasured by the UE comprises the processing delay in the UE.
 5. Themethod of claim 1, wherein the single entity in the wireless network isthe first gNodeB.
 6. The method of claim 5, wherein the first gNodeB isa serving gNodeB for the UE.
 7. The method of claim 1, wherein thesingle entity in the wireless network is a location server.
 8. Themethod of claim 1, wherein the second gNodeB is a neighbor gNodeB of thefirst gNodeB within a communication range.
 9. A user equipment (UE)configured for determining a round-trip time (RTT) for signals betweenthe UE and a plurality of network nodes (gNodeBs) in a wireless network,comprising: a transceiver of the UE configured to: transmit, to at leasta first gNodeB and a second gNodeB, an uplink RTT reference signal;receive, from each of the first gNodeB and the second gNodeB, downlinkRTT reference signals, wherein each of the first gNodeB and the secondgNodeB measure signaling data related to the uplink RTT reference signaland the downlink RTT reference signal transmitted by the first gNodeBand the second gNodeB, wherein the signaling data comprises one of aprocessing delay between a time of arrival (TOA) of the uplink RTTreference signal and a time of transmission (TOT) of the downlink RTTreference signal or a total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal;receive, from a single entity in the wireless network, an aggregatedreport of the measured signaling data for the first gNodeB and thesecond gNodeB; at least one memory; and at least one processor of the UEcoupled to the transceiver and the at least one memory and configured tocalculate a net RTT between the UE and each of the first gNodeB and thesecond gNodeB based on the measured signaling data for the first gNodeBand the second gNodeB received in the aggregated report andcorresponding signaling data measured by the UE, wherein thecorresponding signaling data comprises one of a total RTT between theTOT of the uplink RTT reference signal and the TOA of the downlink RTTreference signal or a processing delay between the TOA of the downlinkRTT reference signal and a TOT of the downlink RTT reference signal, andthe net RTT is determined using the total RTT and the processing delay.10. The UE of claim 9, wherein the at least one processor is furtherconfigured to determine a location of the UE using at least the net RTTbetween the UE and each of the first gNodeB and the second gNodeB and aknown position of the each of the first gNodeB and the second gNodeB.11. The UE of claim 9, wherein the uplink RTT reference signal istransmitted before receiving the downlink RTT reference signals fromeach of the first gNodeB and the second gNodeB, and wherein thesignaling data measured by the first gNodeB and the second gNodeBcomprises the processing delay in the first gNodeB and the secondgNodeB, and the corresponding signaling data measured by the UEcomprises the total RTT.
 12. The UE of claim 9, wherein separate uplinkRTT reference signals are transmitted to the first gNodeB and the secondgNodeB after receiving the downlink RTT reference signals, and whereinthe signaling data measured by the first gNodeB and the second gNodeBcomprises the total RTT, and the corresponding signaling data measuredby the UE comprises the processing delay in the UE.
 13. The UE of claim9, wherein the single entity in the wireless network is the firstgNodeB.
 14. The UE of claim 13, wherein the first gNodeB is a servinggNodeB for the UE.
 15. The UE of claim 9, wherein the single entity inthe wireless network is a location server.
 16. The UE of claim 9,wherein the second gNodeB is a neighbor gNodeB of the first gNodeBwithin a communication range.
 17. A user equipment (UE) configured fordetermining a round-trip time (RTT) for signals between the UE and aplurality of network nodes (gNodeBs) in a wireless network, comprising:means for transmitting, to at least a first gNodeB and a second gNodeB,an uplink RTT reference signal; means for receiving, from each of thefirst gNodeB and the second gNodeB, downlink RTT reference signals,wherein each of the first gNodeB and the second gNodeB measure signalingdata related to the uplink RTT reference signal and the downlink RTTreference signal transmitted by the first gNodeB and the second gNodeB,wherein the signaling data comprises one of a processing delay between atime of arrival (TOA) of the uplink RTT reference signal and a time oftransmission (TOT) of the downlink RTT reference signal or a total RTTbetween the TOT of the downlink RTT reference signal and the TOA of theuplink RTT reference signal; means for receiving, from a single entityin the wireless network, an aggregated report of the measured signalingdata for the first gNodeB and the second gNodeB; and means forcalculating a net RTT between the UE and each of the first gNodeB andthe second gNodeB based on the measured signaling data for the firstgNodeB and the second gNodeB received in the aggregated report andcorresponding signaling data measured by the UE, wherein thecorresponding signaling data comprises one of a total RTT between theTOT of the uplink RTT reference signal and the TOA of the downlink RTTreference signal or a processing delay between the TOA of the downlinkRTT reference signal and a TOT of the downlink RTT reference signal, andthe net RTT is determined using the total RTT and the processing delay.18. The UE of claim 17, further comprising means for determining alocation of the UE using at least the net RTT between the UE and each ofthe first gNodeB and the second gNodeB and a known position of the eachof the first gNodeB and the second gNodeB.
 19. The UE of claim 17,wherein the uplink RTT reference signal is transmitted before receivingthe downlink RTT reference signals from each of the first gNodeB and thesecond gNodeB, and wherein the signaling data measured by the firstgNodeB and the second gNodeB comprises the processing delay in the firstgNodeB and the second gNodeB, and the corresponding signaling datameasured by the UE comprises the total RTT.
 20. The UE of claim 17,wherein separate uplink RTT reference signals are transmitted to thefirst gNodeB and the second gNodeB after receiving the downlink RTTreference signals, and wherein the signaling data measured by the firstgNodeB and the second gNodeB comprises the total RTT, and thecorresponding signaling data measured by the UE comprises the processingdelay in the UE.
 21. The UE of claim 17, wherein the single entity inthe wireless network is the first gNodeB.
 22. The UE of claim 21,wherein the first gNodeB is a serving gNodeB for the UE.
 23. The UE ofclaim 17, wherein the single entity in the wireless network is alocation server.
 24. The UE of claim 17, wherein the second gNodeB is aneighbor gNodeB of the first gNodeB within a communication range.
 25. Anon-transitory storage medium including program code stored thereon, theprogram code is operable to cause at least one processor in a userequipment (UE) to determine a round-trip time (RTT) for signals betweenthe UE and a plurality of network nodes (gNodeBs) in a wireless network,comprising: program code to transmit, to at least a first gNodeB and asecond gNodeB, an uplink RTT reference signal; program code to receive,from each of the first gNodeB and the second gNodeB, downlink RTTreference signals, wherein each of the first gNodeB and the secondgNodeB measure signaling data related to the uplink RTT reference signaland the downlink RTT reference signal transmitted by the first gNodeBand the second gNodeB, wherein the signaling data comprises one of aprocessing delay between a time of arrival (TOA) of the uplink RTTreference signal and a time of transmission (TOT) of the downlink RTTreference signal or a total RTT between the TOT of the downlink RTTreference signal and the TOA of the uplink RTT reference signal; programcode to receive, from a single entity in the wireless network, anaggregated report of the measured signaling data for the first gNodeBand the second gNodeB; and program code to calculate a net RTT betweenthe UE and each of the first gNodeB and the second gNodeB based on themeasured signaling data for the first gNodeB and the second gNodeBreceived in the aggregated report and corresponding signaling datameasured by the UE, wherein the corresponding signaling data comprisesone of a total RTT between the TOT of the uplink RTT reference signaland the TOA of the downlink RTT reference signal or a processing delaybetween the TOA of the downlink RTT reference signal and a TOT of thedownlink RTT reference signal, and the net RTT is determined using thetotal RTT and the processing delay.
 26. The non-transitory storagemedium of claim 25, further comprising program code to determine alocation of the UE using at least the net RTT between the UE and each ofthe first gNodeB and the second gNodeB and a known position of the eachof the first gNodeB and the second gNodeB.
 27. The non-transitorystorage medium of claim 25, wherein the uplink RTT reference signal istransmitted before receiving the downlink RTT reference signals fromeach of the first gNodeB and the second gNodeB, and wherein thesignaling data measured by the first gNodeB and the second gNodeBcomprises the processing delay in the first gNodeB and the secondgNodeB, and the corresponding signaling data measured by the UEcomprises the total RTT.
 28. The non-transitory storage medium of claim25, wherein separate uplink RTT reference signals are transmitted to thefirst gNodeB and the second gNodeB after receiving the downlink RTTreference signals, and wherein the signaling data measured by the firstgNodeB and the second gNodeB comprises the total RTT, and thecorresponding signaling data measured by the UE comprises the processingdelay in the UE.
 29. The non-transitory storage medium of claim 25,wherein the single entity in the wireless network is the first gNodeB.30. The non-transitory storage medium of claim 29, wherein the firstgNodeB is a serving gNodeB for the UE.
 31. The non-transitory storagemedium of claim 25, wherein the single entity in the wireless network isa location server.
 32. The non-transitory storage medium of claim 25,wherein the second gNodeB is a neighbor gNodeB of the first gNodeBwithin a communication range.